common_time: Turn the logging up to 11

Hand merge from ics-aah

> DO NOT MERGE: common_time: Turn the logging up to 11
>
> Actually, despite the CL title, no addition log messages are being
> sent to logcat.  Generally speaking, the common_time service tends to
> be rather quiet from a log perspective.  Events related to master
> election and arbitration as well as state changes tend to be
> infrequent in steady state operation.  Unfortunately, if there is a
> problem with the system, it frequently gets pushed out of logcat by
> other messages and is missing from the logs when a bugreport is
> finally taken.
>
> This change adds a utility class which can be used to store the last N
> log message in a ring buffer to be dumped later during a dumpsys
> operation.  Three internal log buffers were added to the system.  One
> to record messages having to do with state transitions.  Another was
> added to record traffic relating to master election, and one final
> buffer to record basic data on packets which were received but
> discarded for any reason.  During a bugreport, these common_time.clock
> service will be able to dump these messages regardless of the amt of
> other logcat activity, which should assist in debugging long running
> issues.
>
> Change-Id: Ic3bbf7480c8978f9bf82bafaba04cf4586db60cf
> Signed-off-by: John Grossman <johngro@google.com>

Change-Id: If7156d41ce4553d5ba5c3a8e1dd616564a569711
Signed-off-by: John Grossman <johngro@google.com>