Do not filter receiver-driven transferable routes

All in-session transferable routes must be shown in the Output Switcher
regardless of their route features. RouterInfoMediaManager now matches
the behaviour of ManagerInfoMediaManager#getTransferableRoutes.

Test: `adb shell device_config put media_solutions
com.android.settingslib.media.flags.use_media_router2_for_info_media_manager true`
and then verify transferable routes appear in Output Switcher.
Bug: 192657812
Bug: 306391272

Change-Id: Iaaf91a623f3f62f31c2ed20fb58fe10b1a001ead