libaaudio: changes for API council

Removed typedefs like aaudio_sample_rate_t
Removed use of handles. Just pass back opaque pointers.
Simplified gettersi in Stream.
Removed getters from Builder.
Update libaaudio.map.txt

Test: CTS test_aaudio.cpp
Change-Id: I63eaec3e5a8ecc516cfc1f950f4b4f54df1bd518
Signed-off-by: Phil Burk <philburk@google.com>