Add missing unit tests for bcradio service

Added missing unit tests for tuner session, radio module and
conversion utils in broadcast radio service. Also fixed invalid
identifier handling in programSelectorFromHalProgramSelector.

Bug: 282031772
Test: atest BroadcastRadioTests
Flag: TEST_ONLY
Change-Id: Ic2709eb8fc039433585dc2a68505f08c2f441e9e