Disallowed explicit routing for user device affinities conflicts

If user id device affinities for a particular device
disallows playback for a user id, then the explicit audio
routing (#setPreferredDevice) is disallowed. Otherwise,
the explicity routing is allowed.

Bug: 237733218
Test: atest audiopolicy_tests
Change-Id: I823e7e59e86303f80808d4953b52efad5da8e779