Prevent IME predictive back control during hide anim

Insets control should not be granted to ImeBackAnimationController when
there is already a hide animation in progress.

Bug: 362436187
Test: InsetsControllerTest
Flag: android.view.inputmethod.predictive_back_ime
Change-Id: I6284441bc91502c74f03aa6880d0fbb0614e7781
2 files changed