Merge "replace char * with std::string" into rvc-dev am: 56c303b772 am: 22adeeafd8 am: 7a21e39e5f

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/11687549

Change-Id: I21e87eb49a890740aae56a9ce97ccb9aa900a2d0