Fixes a bug where in Android O the all apps search icon appears

on screen rotation.

The fix is by applying a "different" transparent (transparent
white instead of transparent black) for the hint color in focus
state. The root problem lies in DynamicDrawableSpan and restoring
state in EditText if hint color is #000000.

Bug: b/34259116
Change-Id: Id3c46b2af4d5cdb18c0510504f2fe66dece7056f