Rethrow MediaRouter2Manager RemoteExceptions

Said exceptions mean the system server died, after which
guidance suggests it's not a good idea to silently swallow
said exception. Specially considering the client will be
restarted shortly after the system server dies.

Bug: 232812007
Test: atest MediaDeviceManagerTest MediaDataCombineLatestTest CtsMediaBetterTogetherTestCases
Change-Id: I21a724896684d79097ae74df2d5a54e60514ebdf