Merge "[sf] Release the currently presented buffer when setBuffer is called...

Merge "[sf] Release the currently presented buffer when setBuffer is called with null" into udc-dev am: 738654b6 am: 56295928

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22656107



Change-Id: Ideb8b46ab5e66e535d54c055b9a846155025099e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>