Minor improvement to allow an Media3 browser to pass extras
when connecting the initial browser in `MediaControllerImplLegacy`.
Before this change an empty bundle was sent. After this change
the connection hints of the `Media3 browser is used as root hints
of the initial browser that connects when the Media3 browser is
built in `MediaBrowser.buildAsync`.
#cherrypick
PiperOrigin-RevId: 684372552