Added audio policy api to do route based on user.

Added new API to audio policy to route audio output streams based on
Android user id. The routing remains similar to uid rules, with only
using USERID_EXCLUDE_USERID to decide on the user id base routing.
Application uid and stream usage routing remain the same with the added
difference that user id will be taken in to consideration if available.
Bug: 139365417
Test: atest
com.google.android.gts.audio.AudioHostTest#testUserIdDeviceAffinity
Test: atest AudioPlaybackCaptureTest
Change-Id: Ib817eb8ae19ed7dea8451e8a8584a20b9b6f5042