Merge "Revert "Revert "Icon: make Icon's Bitmaps immutable""" into tm-dev am: edea3fd4

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17943164



Change-Id: I927a3aafd7a4cadede4c6031b24656ee99eb15e4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>