[Audiosharing] Fix race condition in AudioSharingRepository provides

BluetoothUtils#isAudioSharingEnabled will check broadcast/assistant
profile support by checking BluetoothAdapter#isLeAudioBroadcastXXXSupported.

BluetoothAdapter#isLeAudioBroadcastXXXSupported can return error value
when BT is not enabled, even broadcast feature is supported.

However, we can not make sure AudioSharingRepository is provided after
BT is enabled during device boot on.

Thus we only check flag when providing AudioSharingRepository, profile
support has already been checked in the repository impl.

Test: atest
Bug: 336716411
Flag: com.android.settingslib.flags.volume_dialog_audio_sharing_fix
Change-Id: I1c9e213e883155e43c90249901d1909873302d1d