Bind mount Android/data and Android/obb individually.

Because we want all other paths (in particular Android/media) to go
through FUSE.

Also use scope_guard to make unwinding some failures easier.

Bug: 151272568
Test: atest AdoptableHostTest
Change-Id: Ib487b9071b5b212c7bb12ce54f80c96d98acaef5
2 files changed