AudioMix address and type, rule exclusion API, dynamic source

- Simplify API for defining an exclusion-based rule: don't define
  an exclusion rule, add instead a way to exclude a rule.
- API for defining rules for dynamic sources (rule match on capture
  preset).
- Verify mix type when creating AudioRecord or AudioTrack for a mix.
- Use hashcode of mix for generating the device address.
- AudioService dump prints info about registered policies.
- Annotate as SystemApi the audio policy-related APIs.
- Express mixing match and exclude rule constants as flags for
  future-proofness

Bug 16006090
Bug 16009464

Change-Id: I0dabe71204501acaffea7ef0ddbbab9700e1bd87