Merge "Don't use String8::empty" into main am: 5b401d3b am: 280d7677 am:...

Merge "Don't use String8::empty" into main am: 5b401d3b am: 280d7677 am: f70ed8f5 am: 89dc5783 am: 017880c7

Original change: https://android-review.googlesource.com/c/platform/frameworks/av/+/2707674



Change-Id: I245a29027fb01b150e584dde18825e1731132603
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>