Updating app uses FFMpeg version used in older version of app

Question

I was using FFMpeg old version in my app and now i updated my app to new FFMpeg version.But when i update my old app version to new app version it still seems to use old version of FFMpeg until i uninstall old app version and then install new app version.I tried programmatically delete cache data in my new version of app using below code but with that also I face problem in some devices which still uses old FFMpeg version-

  private void clearData()
    {
        try {
            PackageInfo pInfo = getPackageManager().getPackageInfo(getPackageName(), 0);
            int mCurrentVersion = pInfo.versionCode;
            SharedPreferences mSharedPreferences = getSharedPreferences("xyz",  Context.MODE_PRIVATE);
            SharedPreferences.Editor mEditor = mSharedPreferences.edit();
            mEditor.apply();
            int last_version = mSharedPreferences.getInt("last_version", -1);
            if(last_version != mCurrentVersion)
            {
                deleteCache(this);
            }
            mEditor.putInt("last_version", mCurrentVersion);
            mEditor.commit();
        } catch (Exception e) {
            FirebaseCrashlytics.getInstance().recordException(e);
        }
    }
    private void deleteCache(Context context) {
        try {
            File dir = context.getCacheDir();
            deleteCacheDir(dir);
        } catch (Exception e) { FirebaseCrashlytics.getInstance().recordException(e);
        }
    }
    private boolean deleteCacheDir(File dir) {
        if (dir != null && dir.isDirectory()) {
            String[] children = dir.list();
            for (int i = 0; i < children.length; i++) {
                boolean success = deleteCacheDir(new File(dir, children[i]));
                if (!success) {
                    return false;
                }
            }
            return dir.delete();
        } else if(dir!= null && dir.isFile()) {
            return dir.delete();
        } else {
            return false;
        }
    }