Merge "IME animation: hide IME-related navbar icons until perceptible" into rvc-dev am: e658c76b5c am: ba68b71a5c

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/11837615

Change-Id: I897a1afc63f971cb8061d02c44dad41ce5b84031