[Audiosharing] Sync sink source when they are combined in CSIP

When users share then pair, we will add source to ther first paired
sink. Once the other sink is grouped with the first one in CSIP, we
should auto sync the source the other sink.

Test: atest
Flag: com.android.settingslib.flags.enable_le_audio_sharing
Bug: 362858921
Change-Id: I599f8cca8eab664b203079081b8d5ea6414aac2a
2 files changed