We currently run (almost) the same code for all track types.
De-duplicate this by using a single method that takes functional
interfaces for track-type dependent logic.
This has the benefit that all track-type dependent logic is
contained within their subclasses and the generic logic doesn't
need to make any assumption about the eligibility of tracks for
selection or adaptation, and doesn't need to access Parameters.
Make this change for audio and text only for now. Video can
be updated in a subsequent change.
PiperOrigin-RevId: 421811411
a9e75d8e3a