Update ExternalStorageProvider volumes with StorageEventListener

We were listening to volume state changes in the
ExternalStorageProvider with the VOLUME_STATE_CHANGED broadcast in the
MountReceiver.

This broadcast can be severly delayed especially on user startup so we
also listen with the StorageEventListener which is more performant.

Test: Manual
Bug: 154332660
Change-Id: I93c43f3b53c0a71cd6aa7cf594fe6988f4bc3f6e