[LE Audio] To remove the broadcast source item that created by receive

state

    - When the user clicks another broadcast source and wants to join,
      we will remove the previous item that created by getAllSource().
      And trigger the search again.

Bug: 242267719
Test: make RunSettingsRoboTests ROBOTEST_FILTER=BluetoothBroadcastSourcePreferenceTest
Test: make RunSettingsRoboTests ROBOTEST_FILTER=BluetoothFindBroadcastsFragmentTest
Change-Id: I416f0a39e31276876e63360664555f99dd7297c9