Indicate whether BandConfig initialization is required or not.

The broadcastradio HAL 1.x requires waiting for onConfigChanged callback
to indicate the initialization is done, while HAL 2.0 does not have the
config setting (at the tuner session level) at all.

This change makes it possible to cleanly workaround race condition in the
radio app retaining support for both HAL revisions. Future versions of the
RadioManager will provide a method to open a session without taking care
about these nuances.

Bug: 74353024
Test: manual
Change-Id: I5de2d5e5c33626fcf0cfbbaf121d0b13e53d0bae