InputRouteManager: only update active type for src

Bug: 355684672
Bug: 367117623
Bug: 411019255
Test: verify active device in UI is consistent
Flag: com.android.media.flags.enable_audio_input_device_routing_and_volume_control
Change-Id: Ib0e594a9e92cbcbf483ebedc1008744a48e50c11