[Predictive Back] AbstractSlideInView#mViewToAnimateInSwipeToDismiss can be private

Bug: 335467443
Test: presubmit
Flag: aconfig com.android.launcher3.enable_predictive_back_gesture TRUNKFOOD
Change-Id: Ibf4b6f04d829daa6a109724c927bf466c25160d5
1 file changed