Merge "[MediaProjection] Store WindowContext in field" into sc-v2-dev am: 47431a3b73 am: b388df4561

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15684817

Change-Id: Ib88096b29b8eeddb8ce850e9256e139cf89ef78f