Refactor IP connectivity event logging

This patch removes static methods for logging IP connectivity events
defined in android.net.metrics and replaces them with a single log()
instance method defined on IpConnectivityLog. Event constructors are
now public also. Every classes logging such events now create an
instance of IpConnectivityLog for logging event objects directly
instantiated with new.

Removing static dependencies allow straightforward testing of logging.

This patch also removes the base IpConnectivityEvent class which is not
needed any more.

Bug: 29035129
Change-Id: I3de700f93f46deaa48a759f938f7d00e1d8bff98
diff --git a/core/java/android/net/metrics/IpManagerEvent.java b/core/java/android/net/metrics/IpManagerEvent.java
index 0940bd0..a390617 100644
--- a/core/java/android/net/metrics/IpManagerEvent.java
+++ b/core/java/android/net/metrics/IpManagerEvent.java
@@ -27,7 +27,7 @@
  * {@hide}
  */
 @SystemApi
-public final class IpManagerEvent extends IpConnectivityEvent implements Parcelable {
+public final class IpManagerEvent implements Parcelable {
 
     public static final int PROVISIONING_OK    = 1;
     public static final int PROVISIONING_FAIL  = 2;
@@ -37,7 +37,8 @@
     public final int eventType;
     public final long durationMs;
 
-    private IpManagerEvent(String ifName, int eventType, long duration) {
+    /** {@hide} */
+    public IpManagerEvent(String ifName, int eventType, long duration) {
         this.ifName = ifName;
         this.eventType = eventType;
         this.durationMs = duration;
@@ -71,7 +72,6 @@
     };
 
     public static void logEvent(int eventType, String ifName, long durationMs) {
-        logEvent(new IpManagerEvent(ifName, eventType, durationMs));
     }
 
     @Override
@@ -84,4 +84,4 @@
         static final SparseArray<String> constants = MessageUtils.findMessageNames(
                 new Class[]{IpManagerEvent.class}, new String[]{"PROVISIONING_", "COMPLETE_"});
     }
-};
+}