Separate AM/FM band in default radio HAL

Separated AM/FM band so that seeking should loop within the band of
the current program info in default AIDL broadcast radio HAL
implementation. Also updated program list by tuner callback when the
AM/FM band is switched.

Bug: 309694368
Test: switch to AM and do not see FM stations in program list in radio KS app
Test: seek in FM band and do not jump any AM stations in radio KS app
Change-Id: Ia4618232d8726f2d779ac2ec87f169b0263ee979