Audio V4: Only expose one notification usage

Too many usages detail were previously exposed to the HAL.
All usages that should be handled identically by the HAL
are now the same value.

 - All notification types are now the same usages

Test: build
Bug: 38184704
Change-Id: I2096f995e249ab02bc29449c6d1a65b521dc13f7
Signed-off-by: Kevin Rocard <krocard@google.com>