unable to update published android app apk on google play

Question

I'm trying to update my published android app by uploading another apk from appRelase then edit release but when i upload the apk it says

couldn't save your changes

android {
compileSdkVersion 29
buildToolsVersion "29.0.0"
defaultConfig {
    applicationId "com.techno.kashfrohaanyappmahkotf"
    minSdkVersion 17
    targetSdkVersion 29
    versionCode 2
    versionName "2.0"
    multiDexEnabled true
    vectorDrawables.useSupportLibrary = true
    testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
    ndk.abiFilters 'armeabi-v7a', 'arm64-v8a', 'x86', 'x86_64'
}

compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
}
buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro'
    }
}
}