Merge changes from topic "nullablecollection" am: 60f3d5cee4 am: 57dd6872fd

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1567165

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ia6baaacb15e7575f837da727ecbe6643dd93dfb4