Handle CAMSM initialization and Runnable cases in Logging

Add a session to TelecomSystem when it is initialized to track that
entry point as well as provide the CAMSM a session for its
initialization. Also only run Log.endSession on a Telecom Runnable if
the subsession that was created was not cancelled (and is now equal to null).

Change-Id: Iaa895afe44855a8862d9d7b0a61d465561bfacd0