Avoid notifying the FUSE daemon for invisible volumes

Invisible volumes/USB OTG volumes are neither exposed to apps nor the
MediaStore. Calling into the FUSE daemon for invisible volumes can
lead to unexpected exceptions if the MediaProvider tries to get more
information about the StorageVolume from the StorageManagerService

Test: Manual
Bug: 163679723
Change-Id: I9e5e3418c1da15e61942fbedcf440ecca6cdca8c