Replace string copies with const-ref am: 121fedaa46 am: e331953c90 am: dc5d0250c6

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2869314

Change-Id: I8d11e83246a4fe701434c20f5173fa1e4c725471
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>