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

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



Change-Id: If61299452345b2c213cea323689b98c3a95d6e92
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>