Merge "Revert "Icon: make Icon's Bitmaps immutable"" into tm-dev am: 4e8c47ef am: cd3ac5bf

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17919920



Change-Id: Icd7f3675dbc2f9b16644fdf99bca03fe34a0e080
Ignore-AOSP-First: this is an automerge
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>