Q:

Permission Denial: writing android.support.v4.content.FileProvider uri

Good day.I have an weird issue to which none of examples in stack overflow has worked.I am opening an gallery,after which i am redirecting user to crop intent.Important to mention that this only happens on android N and not below devices.The issue is that this exception is thrown as soon as the crop is done..I dont know what causes this,but actually here is how i start crop intent.
 Intent cropIntent = new Intent("com.android.camera.action.CROP");
    cropIntent.addFlags(Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);

    Uri outPutUri = FileProvider.getUriForFile(activity, activity.getApplicationContext().getPackageName() + ".provider", new File(output));
    Uri photoURI = FileProvider.getUriForFile(activity, activity.getApplicationContext().getPackageName() + ".provider", new File(path));

    activity.grantUriPermission("com.android.camera.action.CROP", outPutUri, Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);
    activity.grantUriPermission("com.android.camera.action.CROP", photoURI, Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);

    cropIntent.setDataAndType(photoURI, "image/*");

    cropIntent.putExtra("crop", "true");

    cropIntent.putExtra("aspectX", aspectX);
    cropIntent.putExtra("aspectY", aspectY);

    cropIntent.putExtra(MediaStore.EXTRA_OUTPUT, outPutUri);

    activity.startActivityForResult(cropIntent, CROP_REQUEST);

I have granted the Uri permission,have added these to manifest
  <provider
        android:name="android.support.v4.content.FileProvider"
        android:authorities="${applicationId}.provider"
        android:exported="false"
        android:grantUriPermissions="true">
        <meta-data
            android:name="android.support.FILE_PROVIDER_PATHS"
            android:resource="@xml/provider_paths"/>

I have tried all stack over flow answer examples,there is no more issue on stack overflow with this scenario and not any of them have worked.So what is the issue with android N ?Should it be so hard?
This is the exception which is being thrown
FATAL EXCEPTION: main
Process: com.android.gallery3d, PID: 5735
java.lang.SecurityException: Permission Denial: writing android.support.v4.content.FileProvider uri content://my.package.name/external_files/Android/data/my.package.name/cache/0.5062300225583558.png from pid=5735, uid=10071 requires the provider be exported, or grantUriPermission()
at android.os.Parcel.readException(Parcel.java:1683)
at android.database.DatabaseUtils.readExceptionFromParcel(DatabaseUtils.java:183)
at android.database.DatabaseUtils.readExceptionWithFileNotFoundExceptionFromParcel(DatabaseUtils.java:146)
at android.content.ContentProviderProxy.openAssetFile(ContentProviderNative.java:621)
at android.content.ContentResolver.openAssetFileDescriptor(ContentResolver.java:1000)
at android.content.ContentResolver.openOutputStream(ContentResolver.java:742)
at android.content.ContentResolver.openOutputStream(ContentResolver.java:718)
at com.android.gallery3d.filtershow.crop.CropActivity$BitmapIOTask.<init>(CropActivity.java:408)
at com.android.gallery3d.filtershow.crop.CropActivity.startBitmapIO(CropActivity.java:339)
at com.android.gallery3d.filtershow.crop.CropActivity.startFinishOutput(CropActivity.java:311)
at com.android.gallery3d.filtershow.crop.CropActivity$1.onClick(CropActivity.java:117)
at android.view.View.performClick(View.java:5610)
at android.view.View$PerformClick.run(View.java:22260)
at android.os.Handler.handleCallback(Handler.java:751)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:154)
at android.app.ActivityThread.main(ActivityThread.java:6077)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:865)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:755)
09-30 13:19:44.376 11909-11942/volo.global.pingbing E/FA: Task exception on worker thread: java.lang.IncompatibleClassChangeError: The method 'java.io.File android.support.v4.content.ContextCompat.getNoBackupFilesDir(android.content.Context)' was expected to be of type virtual but instead was found to be of type direct (declaration of 'com.google.firebase.iid.zzg' appears in /data/app/volo.global.pingbing-1/base.apk): com.google.android.gms.measurement.internal.zzt.zzEd(Unknown Source)

A:

List<ResolveInfo> resInfoList = getPackageManager().queryIntentActivities(intent, PackageManager.MATCH_DEFAULT_ONLY);
        for (ResolveInfo resolveInfo : resInfoList) {
            String packageName = resolveInfo.activityInfo.packageName;
            grantUriPermission(packageName, photoURI, Intent.FLAG_GRANT_WRITE_URI_PERMISSION | Intent.FLAG_GRANT_READ_URI_PERMISSION);
        }

