Derestrict RippleDrawable.mState.

Usage has been discovered by an app so reverting this to its previous
state. This is conceptually a partial revert of change 5d123b67.

NoNonSdkCheck: b/170729553

Bug: 175939224
Test: m
Change-Id: I277b085b490407bbe1899dd7f4614f51cd9ce36e