Replace string copies with const-ref am: 121fedaa am: e331953c am: dc5d0250

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>