Merge "[Mainline] Migrate TextUtils#emptyIfNull" am: 23438d66dd am: 562a34498f

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1550514

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ie90c6d0245703243f66a9bc2e4d0bf512b3e6339