Merge "Revert "Revert "Remove IME surface when occured in multi-window mode"""...

Merge "Revert "Revert "Remove IME surface when occured in multi-window mode""" into rvc-dev am: 8ec4d3a3

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/11862408

Change-Id: Ice5c7f823c0f7a353d65eabea1f959853e3f6ed8