Add self-managed connection service API.

Beginning of required changes to support self-managed CS.
1. Ensure self-managed connections have PROPERTY_SELF_MANAGED set.
2. Plumb through setAudioRoute API from connection.
3. Ensure self-managed phone accounts are auto-enabled.
4. Stub out new TelecomManager APIs.

Test: Manual; cts and unit tests will come in future CLs.
Bug: 34159263
Change-Id: I8352b2e2e3f9424ac1b612280c1b0cdca006afdb