Fix output switcher initiator data

Also remove redundant transfer method that takes initiation data as
parameters. The initiator should always be the target package of the
router.

Bug: b/319645714
Flag: com.android.media.flags.enable_built_in_speaker_route_suitability_statuses
Test: Using the media routing sample app.
Test: atest SystemMediaRouter2Test

Change-Id: I8ce16d8380b5e6ee04cbcbc6cf57a418595f2cc1