[Media TTT] Add transferToThisDeviceTriggered callback.

Bug: 203800643
Bug: 203800347
Test: `adb shell cmd statusbar media-ttt-chip-add-sender Device
TransferToThisDeviceTriggered` triggers a chip saying "Playing on this
device" with loading icon
Test: media.taptotransfer tests

Change-Id: Iddc0593603f7fdd96a67b805a808205e77658d8d