Source - http://android-developers.blogspot.in/2016/02/android-support-library-232.html
when using AppCompat with ImageView (or subclasses such as ImageButton
and FloatingActionButton), you’ll be able to use the new app:srcCompat
attribute to reference vector drawables (as well as any other drawable
available to android:src):
where you can define your app in your root element as
xmlns:app="http://schemas.android.com/apk/res-auto"
