audio policy: set track spatialization state from audio policy manager.

When an audio track is created, AudioPolicyManager.getOutputForAttr()
will return if it is actually being spatialized. This will allow removing
the duplicated logic in audio flinger to tell if a track is spatialized and
also to only enable the spatializer effect if spatialized tracks are active
and connected to the spatializer mixer.

Bug: 227740874
Test: music and spatial audio playback regression
Change-Id: If75c8ad06afdf3b47e3cc5d30c777af22d6fc35e