Connectivity metrics: simplify ConnectivityMetricsEvent

Now that ConnectivityMetricsEvent is only used for core networking
metrics and is not @SystemApi anymore, remove unused fields and prepare
for additional new fields.

Test: updated unit tests, $ runtest frameworks-net passes
Bug: 34901696
Change-Id: I15abad19981d491f16f2a3afe401f1e833079907
diff --git a/core/java/android/net/ConnectivityMetricsEvent.java b/core/java/android/net/ConnectivityMetricsEvent.java
index 6fdc739..1b1b958 100644
--- a/core/java/android/net/ConnectivityMetricsEvent.java
+++ b/core/java/android/net/ConnectivityMetricsEvent.java
@@ -23,35 +23,24 @@
 public final class ConnectivityMetricsEvent implements Parcelable {
 
     /**  The time when this event was collected, as returned by System.currentTimeMillis(). */
-    final public long timestamp;
-
-    /** The subsystem that generated the event. One of the COMPONENT_TAG_xxx constants. */
-    final public int componentTag;
-
-    /** The subsystem-specific event ID. */
-    final public int eventTag;
+    public long timestamp;
 
     /** Opaque event-specific data. */
-    final public Parcelable data;
+    public Parcelable data;
 
-    public ConnectivityMetricsEvent(long timestamp, int componentTag,
-                                    int eventTag, Parcelable data) {
-        this.timestamp = timestamp;
-        this.componentTag = componentTag;
-        this.eventTag = eventTag;
-        this.data = data;
+    public ConnectivityMetricsEvent() {
+    }
+
+    public ConnectivityMetricsEvent(Parcel in) {
+        timestamp = in.readLong();
+        data = in.readParcelable(null);
     }
 
     /** Implement the Parcelable interface */
     public static final Parcelable.Creator<ConnectivityMetricsEvent> CREATOR
             = new Parcelable.Creator<ConnectivityMetricsEvent> (){
         public ConnectivityMetricsEvent createFromParcel(Parcel source) {
-            final long timestamp = source.readLong();
-            final int componentTag = source.readInt();
-            final int eventTag = source.readInt();
-            final Parcelable data = source.readParcelable(null);
-            return new ConnectivityMetricsEvent(timestamp, componentTag,
-                    eventTag, data);
+            return new ConnectivityMetricsEvent(source);
         }
 
         public ConnectivityMetricsEvent[] newArray(int size) {
@@ -59,7 +48,6 @@
         }
     };
 
-    /** Implement the Parcelable interface */
     @Override
     public int describeContents() {
         return 0;
@@ -68,13 +56,11 @@
     @Override
     public void writeToParcel(Parcel dest, int flags) {
         dest.writeLong(timestamp);
-        dest.writeInt(componentTag);
-        dest.writeInt(eventTag);
         dest.writeParcelable(data, 0);
     }
 
+    @Override
     public String toString() {
-        return String.format("ConnectivityMetricsEvent(%tT.%tL, %d, %d): %s",
-                timestamp, timestamp, componentTag, eventTag, data);
+        return String.format("ConnectivityMetricsEvent(%tT.%tL): %s", timestamp, timestamp, data);
     }
 }
diff --git a/core/java/android/net/metrics/IpConnectivityLog.java b/core/java/android/net/metrics/IpConnectivityLog.java
index 173e5fd..aaad1fa 100644
--- a/core/java/android/net/metrics/IpConnectivityLog.java
+++ b/core/java/android/net/metrics/IpConnectivityLog.java
@@ -74,7 +74,10 @@
         }
 
         try {
-            int left = mService.logEvent(new ConnectivityMetricsEvent(timestamp, 0, 0, data));
+            ConnectivityMetricsEvent ev = new ConnectivityMetricsEvent();
+            ev.timestamp = timestamp;
+            ev.data = data;
+            int left = mService.logEvent(ev);
             return left >= 0;
         } catch (RemoteException e) {
             Log.e(TAG, "Error logging event", e);
diff --git a/tests/net/java/com/android/server/connectivity/IpConnectivityMetricsTest.java b/tests/net/java/com/android/server/connectivity/IpConnectivityMetricsTest.java
index 1f7c5f4..5d34c5c 100644
--- a/tests/net/java/com/android/server/connectivity/IpConnectivityMetricsTest.java
+++ b/tests/net/java/com/android/server/connectivity/IpConnectivityMetricsTest.java
@@ -304,14 +304,15 @@
     }
 
     static ConnectivityMetricsEvent expectedEvent(int timestamp) {
-        return new ConnectivityMetricsEvent((long)timestamp, 0, 0, FAKE_EV);
+        ConnectivityMetricsEvent ev = new ConnectivityMetricsEvent();
+        ev.timestamp = timestamp;
+        ev.data = FAKE_EV;
+        return ev;
     }
 
     /** Outer equality for ConnectivityMetricsEvent to avoid overriding equals() and hashCode(). */
     static void assertEventsEqual(ConnectivityMetricsEvent expected, ConnectivityMetricsEvent got) {
         assertEquals(expected.timestamp, got.timestamp);
-        assertEquals(expected.componentTag, got.componentTag);
-        assertEquals(expected.eventTag, got.eventTag);
         assertEquals(expected.data, got.data);
     }
 
diff --git a/tests/net/java/com/android/server/connectivity/MetricsTestUtil.java b/tests/net/java/com/android/server/connectivity/MetricsTestUtil.java
index c5965e8..5064b9b 100644
--- a/tests/net/java/com/android/server/connectivity/MetricsTestUtil.java
+++ b/tests/net/java/com/android/server/connectivity/MetricsTestUtil.java
@@ -28,7 +28,10 @@
     }
 
     static ConnectivityMetricsEvent ev(Parcelable p) {
-        return new ConnectivityMetricsEvent(1L, 0, 0, p);
+        ConnectivityMetricsEvent ev = new ConnectivityMetricsEvent();
+        ev.timestamp = 1L;
+        ev.data = p;
+        return ev;
     }
 
     static ConnectivityMetricsEvent describeIpEvent(Consumer<Parcel>... fs) {