IP Connectivity metrics: add connect() statistics

This patch adds a ConnectStats class to aggregate connect() statistics
gathered in NetdEventListenerService. ConnectStats is uploaded once a
day by IpConnectivityMetrics.

Test: $ runtest frameworks-net + new unit test
Bug: 32198976
Change-Id: Iea63339035415513a5ba0ff4b8f4d79f75fc652d
diff --git a/tests/net/java/com/android/server/connectivity/IpConnectivityMetricsTest.java b/tests/net/java/com/android/server/connectivity/IpConnectivityMetricsTest.java
index 60628ec..e9257fa 100644
--- a/tests/net/java/com/android/server/connectivity/IpConnectivityMetricsTest.java
+++ b/tests/net/java/com/android/server/connectivity/IpConnectivityMetricsTest.java
@@ -292,10 +292,5 @@
     }
 
     static final Comparator<ConnectivityMetricsEvent> EVENT_COMPARATOR =
-        new Comparator<ConnectivityMetricsEvent>() {
-            @Override
-            public int compare(ConnectivityMetricsEvent ev1, ConnectivityMetricsEvent ev2) {
-                return (int) (ev1.timestamp - ev2.timestamp);
-            }
-        };
+        Comparator.comparingLong((ev) -> ev.timestamp);
 }