Merge "Have the StackCoordinator attach the GroupExpansionManagerImpl to the...

Merge "Have the StackCoordinator attach the GroupExpansionManagerImpl to the Pipeline" into udc-dev am: 2fde8209 am: 18499214 am: c0a791f1

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22646453



Change-Id: Ie79c9aad6bf4a1a9076cc6f6b8cd719ad6efef8f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>