[flexiglass] Pattern bouncer motion UX polish. am: 70f9b87d am: 79929b99...

[flexiglass] Pattern bouncer motion UX polish. am: 70f9b87d am: 79929b99 am: 3130b0a5 am: bf0c93a5

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/23351960



Change-Id: I87f53d85fe249d7c3961a22924e0e35ea23c29d7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>