Audio V5: move Stream Metadata to common

So that it can be used by the Bluetooth HAL.

Test: compile
Change-Id: I2e2b1e12e1f837183c4edbd1d330a13a67d1ecae
Merged-In: I2e2b1e12e1f837183c4edbd1d330a13a67d1ecaf
Signed-off-by: Kevin Rocard <krocard@google.com>