Update device name on audio info changed

Bug: 168125184
Test: manual - Cast Spotify. Dismiss app in overview. Open Spotify while
still casting. Verify cast icon appears for output switcher.

Change-Id: I134a5a916ac1347016cf56f44b89109c0f5fa2c7
(cherry picked from commit fb1beb5c)
Merged-In: I134a5a916ac1347016cf56f44b89109c0f5fa2c7