Merge "Allow IME to register system back callbacks in...

Merge "Allow IME to register system back callbacks in ImeOnBackInvokedDispatcher#switchRootView." into tm-qpr-dev am: 467383f0 am: 9970ac99

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/20874663



Change-Id: I78d1e82263f985af14b54db6487f16e5f1a11ed4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>