Move event logging to TransportClient and add connection event

Move event logging from registration to TransportClient and add new
event for connection.

Change-Id: I32022590a36b6f28f960e91f8880a0430e862852
Ref: http://go/br-binding-on-demand
Bug: 17140907
Test: m -j RunFrameworksServicesRoboTest
Test: adb logcat -b events, check relevant events
5 files changed