Implement new common_time service functionality.

Major re-factor of the common_time (formally aah_timesrv) service in
preparation for up-integration into Android master.  This work
includes bug fixes, new features, and general code cleanup.  High
points are listed below.

+ CommonClock interface has been enhanced to allow querying of many
  more low level synchronization details; mostly for debugging, but in
  theory useful to an application as well.
+ CommonTimeConfig interface has been implemented.  This allows a
  management process to configure a number of different parameters
  (many of them new) to control the behavior of the common_time
  service.  Most importantly, the time service can be bound to a
  specific network interface and should only operate on that interface
  an no others.
+ Enhance log messages to be more useful in determining what the time
  service state machine is doing and why.
+ Enhance information provided by dumpsys to provide many more details
  about the quality of time sync and the network conditions which gave
  rise to the current quality conditions.

Features, features, features....
+ Add a feature which lets the high level choose a different master
  election endpoint so that multiple time synchronization domains can
  co-exist on the same subnet (mostly to support a potential use case
  of multiple home domains in a multiple dwelling environment like a
  hotel, dormitory or apartment complex).
+ Add a feature which lets the high level assign a 64-bit group ID
  which allows partitioning of time synchronization domains even when
  the master election endpoint is shared (as it might be if broadcast
  is being used instead of multicast)
+ Add an auto-disable feature which lets the time service drop into
  network-less mode when there are no active clients of the
  common_time service in the device.  Mostly for phones, this allows
  phones to not consume network/battery resources when they don't need
  to maintain common time.
+ Add a feature which lets the high level choose the priority of the
  common_time service in the master election protocol.  This allows
  high level decisions about things like mobile vs non-mobile, wired
  ethernet vs WiFi to affect who ends up with the job of master on a
  given network.  Priority overrides at the low level also allow
  clients coming in from network-less mode to lower their effective
  priority as they join a new network so as to not disrupt any
  stable long-running timeline which may already be active on the
  network.
+ Add the ability to control some of the core parameters of the time
  sync service which effect network load (like the sync polling
  interval and the master announce interval)

Change-Id: I71af15a83cfa5ef0417b406928967fb9e02f55c6
15 files changed