Update CMD association flow.

Adapt CDM Association flow for new associate() API, which supports
self-managed associations.
Add support for new device profiles: APP_STREAMING and
AUTOMOTIVE_PROJECTION.
Start CDM discovery service only after UI is visible.
Lift "one request at a time" limitation (remove
AssociationRequestsProcessor.mRequest field).

Bug: 194301022
Bug: 208307075
Test: atest CtsCompanionDevicesTestCases:AssociateTest
Test: atest CtsCompanionDevicesTestCases:AssociateSelfManagedTest
Test: atest CtsCompanionDevicesTestCases
Change-Id: I6cb796c375421f101e87ad436111996495eb74d9