audio: Add DriverInterface::start method am: 49712b56d8 am: d8e545d9d8 am: 4eb39af463 am: 5e9873805d am: 9a652231e0 am: ef83280c00

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2647304

Change-Id: I43852509f7326b8ab5010ca9f92514668be06b72
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>