Merge "Split-shade: prevent new shade expansion when shade already expanded"...

Merge "Split-shade: prevent new shade expansion when shade already expanded" into tm-dev am: 9cbaca73 am: 17633036

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17940788



Change-Id: I99ebc388dbaec54239492f317aa1b7d24b186bd4
Ignore-AOSP-First: this is an automerge
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>