Merge "Use std::optional instead of std::unique_ptr" am: 85486fc425 am: 17f086a93a am: 61c1e0c729

Original change: https://android-review.googlesource.com/c/platform/frameworks/av/+/1501913

Change-Id: I5dd75caac248cf553d3a20bfb63ea8eb06915784