Merge "Don't use String8::empty" into main am: 5f0cfee3 am: 5028887a am:...

Merge "Don't use String8::empty" into main am: 5f0cfee3 am: 5028887a am: 94418c8d am: c4f72ace

Original change: https://android-review.googlesource.com/c/platform/frameworks/av/+/2722496



Change-Id: I1f6d2ef09f6f7893c3c1033b7cf65ae8bea174a5
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>