Fix srcCompat set ordering issue

If srcCompat is set, it will always overwrite
android:src. This isn't what most developers
expect though so we'll flip the ordering so
that android:src overwrites srcCompat.

This allows developers to override AppCompat
styles which use srcCompat, with drawables set
with android:src.

BUG: 28613558
Change-Id: I927123a06b2ce4d762920564c9e545f6ede48734
3 files changed