audiohal: Re-implement stream read and write using FMQ

Result: no hwbinder calls due read / write session.

Added IStream.close method for explicitly freeing up of resources
consumed by the stream before automatic server objects reaping
gets to it.

Test: make, perform Loopback RTT, check traces
Bug: 30222631
Change-Id: I678559f6ef30026685df787cd2ba7c2ee449ed27