Admob Native ads not showing in below android 4.4 devices but showing in android 5.0 plus devices

Question

I have tested the app with below Android 4.4 devices, interstitial ads are showing but the native ads are not showing up and the app is working fine by showing interstitial and native ads in 5.0 plus devices.

I hope the code is working fine as the native are showing in android 5.0 devices but how native ads can be shown in below android 4.4 devices

I hope anyone help me

Here is build.gradle

apply plugin: 'com.android.application'

android {
    compileSdkVersion 23
    buildToolsVersion "23.0.2"
    useLibrary 'org.apache.http.legacy'

    packagingOptions {
        exclude 'META-INF/DEPENDENCIES'
        exclude 'META-INF/NOTICE'
        exclude 'META-INF/LICENSE'
        exclude 'META-INF/LICENSE.txt'
        exclude 'META-INF/NOTICE.txt'
    }
    defaultConfig {
        applicationId "com.test.app"
        minSdkVersion 9
        targetSdkVersion 23
       // multiDexEnabled true
    }

    buildTypes {
        release {
            minifyEnabled false
            proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.txt'
        }
    }
}

dependencies {
    compile files('libs/acra-4.5.0.jar')
    compile 'com.android.support:support-v4:23.1.1'
    compile 'com.android.support:appcompat-v7:23.1.1'
    compile 'com.google.code.gson:gson:1.6'
    compile 'com.google.android.gms:play-services-ads:9.2.1'
    //compile 'com.google.android.gms:play-services-identity:9.2.1'
    compile 'com.firebase:firebase-client-android:2.3.1'
    compile 'com.google.android.gms:play-services-gcm:9.2.1'
    //compile 'org.apache.httpcomponents:httpcore:4.4.1'
    //compile 'org.apache.httpcomponents:httpclient:4.5'
    compile 'com.google.android.gms:play-services-analytics:9.2.1'
}

Here is Layout

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:ads="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="53dp"
        android:background="#3F51B5"
        android:orientation="vertical">

        <ImageView
            ..

        <TextView
            ...

        <TextView
            android:layout_width="match_parent"
            android:layout_height="2dp"
            android:layout_alignParentBottom="true"
            android:background="#000000"
            android:text="" />
    </RelativeLayout>

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="bottom"
        android:gravity="bottom"
        android:orientation="vertical">

        <com.google.android.gms.ads.AdView
            android:id="@+id/adView2"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            ads:adSize="SMART_BANNER"
            ads:adUnitId="@string/native_ad_unit_id" />
    </LinearLayout>

    <LinearLayout
        about listview ......

        <ListView
            android:id="@+id/lvMenu"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:divider="#ffffff"
            android:dividerHeight="2dp"
            android:minHeight="70dp" />
    </LinearLayout>

Styles file

<!-- Base application theme. -->
    <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar">
        <!-- Customize your theme here. -->
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="colorPrimaryDark">@color/colorPrimaryDark</item>
        <item name="colorAccent">@color/colorAccent</item>
    </style>

    <style name="AppTheme.NoActionBar">
        <item name="windowActionBar">false</item>
        <item name="windowNoTitle">true</item>
    </style>

    <style name="AppTheme.AppBarOverlay" parent="ThemeOverlay.AppCompat.Dark.ActionBar" />

    <style name="AppTheme.PopupOverlay" parent="ThemeOverlay.AppCompat.Light" />

</resources>

Manifest File

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.test.app"
    android:versionCode="1"
    android:versionName="1.1">

    <uses-sdk
        android:minSdkVersion="9"
        android:targetSdkVersion="23" />

    <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
    <uses-permission android:name="android.permission.READ_PHONE_STATE" />

    <supports-screens
        android:anyDensity="true"
        android:largeScreens="true"
        android:normalScreens="true"
        android:requiresSmallestWidthDp="100"
        android:resizeable="true"
        android:smallScreens="true"
        android:xlargeScreens="true" />

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

    <application
        android:name=".newApplication"
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@android:style/Theme.NoTitleBar.Fullscreen">
        <activity
            android:name=".SplachActivity"
            android:label="@string/app_name">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
         <activity
            android:name="com.google.android.gms.ads.AdActivity"
            android:configChanges="keyboard|keyboardHidden|orientation|screenLayout|uiMode|screenSize|smallestScreenSize"
            android:theme="@android:style/Theme.Translucent" />

        <meta-data
            android:name="com.google.android.gms.version"
            android:value="@integer/google_play_services_version" />


    </application>

</manifest>