Merge "Do not register OnBackInvokedCallback for SoftInputWindow." into udc-dev am: a2e448b25f am: 720b522cbe

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/24677183

Change-Id: If970588271f03257605163c77846d2623998c338
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>