Merge "Drop String::empty()" into main am: 47fc3df9a0

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2707114

Change-Id: If551ac01d8dcfc5862888b561f3a99a01c1f6540
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>