Merge "Split-shade: prevent new shade expansion when shade already expanded" into tm-dev am: 9cbaca73 am: 10eaf1c6 am: dc5c4231

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



Change-Id: I916aba5a18c7f072f4d840b38b7277c187f17022
Ignore-AOSP-First: this is an automerge
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>