Merge "When detaching player, set to null before clean-up" into udc-dev am:...

Merge "When detaching player, set to null before clean-up" into udc-dev am: 61c04730 am: 861ec15f

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/22752080



Change-Id: Ieacbf0842f3feca4216e8441a3d3cdf5f06ce2d9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>