audio_hal_interface: Add ProviderInfo class

Caches the information returned by getProviderInfo
for a2dp hardware offloading encoding and decoding paths.
Assigns codec indexes for unknown codecs.

Bug: 308958546
Bug: 308686081
Test: m com.android.btservices
Change-Id: If33a3755e5ad9f1c7f8afd46cd291ef2910f7bef