New IpConnectivityMetrics service

This patch defines a new metrics service for IpConnectivity events
defined in android.net.metrics, separate from currently existing
MetricsLoggerService.

Similarly to MetricsLoggerService, the new service has an event buffer.
It also implements a dumpsys interface that can be used to flush events
and output a serialized proto.

Bug: 31254800
Change-Id: I0c3faeb4008b283f85d9ba9460371fa68956ea3b
diff --git a/Android.mk b/Android.mk
index 41966f4..d765e9c 100644
--- a/Android.mk
+++ b/Android.mk
@@ -200,6 +200,7 @@
 	core/java/android/net/ICaptivePortal.aidl \
 	core/java/android/net/IConnectivityManager.aidl \
 	core/java/android/net/IConnectivityMetricsLogger.aidl \
+	core/java/android/net/IIpConnectivityMetrics.aidl \
 	core/java/android/net/IEthernetManager.aidl \
 	core/java/android/net/IEthernetServiceListener.aidl \
 	core/java/android/net/INetworkManagementEventObserver.aidl \