[automerger skipped] Extract ExpandableControllerImpl out of Expandable am: 227e6c78e9 -s ours am: 2c63169606 -s ours

am skip reason: Merged-In Iaa39a2c75e8a49770eaf5d8ce66d5ac562d9320c with SHA-1 bde9b5f28f is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/20164144

Change-Id: Ie8ce0c61023703b3b259ddd204c451bd1c984508
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>