DO NOT MERGE Fixes in comments for NetworkEvent, DnsEvent and ConnectEvent

Test: the APIs will be tested by CTS when unhidden
Bug: 29748723

(cherry picked from commit da9d3ad3ac)

Change-Id: Iaff05eb6d4a2fd12e0271c703d694ecfc0dc9a17

core/java/android/app/admin/ConnectEvent.java

@@ -31,6 +31,7 @@ public final class ConnectEvent extends NetworkEvent implements Parcelable {
     /** The destination port number. */
     private final int port;
 
+    /** @hide */
     public ConnectEvent(String ipAddress, int port, String packageName, long timestamp) {
         super(packageName, timestamp);
         this.ipAddress = ipAddress;

core/java/android/app/admin/DnsEvent.java

@@ -37,6 +37,7 @@ public final class DnsEvent extends NetworkEvent implements Parcelable {
      */
     private final int ipAddressesCount;
 
+    /** @hide */
     public DnsEvent(String hostname, String[] ipAddresses, int ipAddressesCount,
             String packageName, long timestamp) {
         super(packageName, timestamp);

core/java/android/app/admin/NetworkEvent.java

@@ -16,6 +16,7 @@
 
 package android.app.admin;
 
+import android.content.pm.PackageManager;
 import android.os.Parcel;
 import android.os.Parcelable;
 import android.os.ParcelFormatException;
@@ -35,21 +36,29 @@ public abstract class NetworkEvent implements Parcelable {
     /** The timestamp of the event being reported in milliseconds. */
     long timestamp;
 
-    protected NetworkEvent() {
+    /** @hide */
+    NetworkEvent() {
         //empty constructor
     }
 
-    protected NetworkEvent(String packageName, long timestamp) {
+    /** @hide */
+    NetworkEvent(String packageName, long timestamp) {
         this.packageName = packageName;
         this.timestamp = timestamp;
     }
 
-    /** Returns the package name of the UID that performed the query. */
+    /**
+     * Returns the package name of the UID that performed the query, as returned by
+     * {@link PackageManager#getNameForUid}.
+     */
     public String getPackageName() {
         return packageName;
     }
 
-    /** Returns the timestamp of the event being reported in milliseconds. */
+    /**
+     * Returns the timestamp of the event being reported in milliseconds, the difference between
+     * the time the event was reported and midnight, January 1, 1970 UTC.
+     */
     public long getTimestamp() {
         return timestamp;
     }