Merge commit 'a19056c3' into nyc-mr1-dev-plus-aosp

* commit 'a19056c3': (35 commits)
  NetworkMonitor: send one DNS probe per web probe
  NetworkMonitor metrics: add first validation information
  APF: also drop any ICMPv6 RSs
  ConnectivityServiceTest: fix testAvoidBadWifiSettings
  Fix ConnectivityServiceTest testRequestBenchmark
  Switch over to new "time.android.com" NTP pool.
  Define API for metering network stats buckets.
  Refactored NetworkStatsServiceTest to use Mockito instead of EasyMock.
  Use @Ignore to explicitly disable a @test method.
  Fixed NetworkStatsServiceTest and converted it to JUnit4.
  VPN network stat accounting changes.
  ConnectivityThread: use lazy holder idiom
  ConnectivityManager: use ConnectivityThread looper
  ConnectivityManager: a simpler CallbackHandler
  Indicate the NsdServiceInfo attributes are only filled in for a resolved service.
  Add a null check for the OnStartTetheringCallback.
  TokenBucket for rate-limiting and throttling
  IpConnectivityMetrics reads buffer size in settings
  CaptivePortalLogin: set mixed content policy to compatibility.
  Add IP conn metrics to dumpsys and bug reports
  ...