oboeservice: call to hal again to close transport FD by binder

- base on hardware binder design, the transport data from binder will be
closed on the next transact(...).
- Here AAudio call to Audio HAL again to trigger BC_FREE_BUFFER to
release previous data (the shared FD from Audio HAL by createMmapBuffer)
in binder driver.

Bug: 187502463

Test: open/close mmap several times.

Signed-off-by: Jasmine Cha <chajasmine@google.com>
Change-Id: I82ae6d1c62fc12f90f2b18641920e239c3632891