tree 30170b5a9bcdb32d8391c807acab1f55ba23c442
parent 5bc68e02a01c2621aa64e2d410a2caa6c97bc190
author Jooyung Han <jooyung@google.com> 1605669470 +0900
committer Jooyung Han <jooyung@google.com> 1605672751 +0900

midi: Use std::optional instead of std::unique_ptr

Since Android R, Parcel provides read/write methods for "@nullable"
values using std::optional.

Bug: 149784838
Test: m
Change-Id: I5c6a87072ced2f2a3a16df374244bb0aff5f9cb3