Add @Nullable to Object#equals()

This is a partial cherry-pick of change:
I5eedb571c9d78862115dfdc5dae1cf2a35343580

for connectivity classes.

Bug: 170883422
Test: m
Merged-In: I5eedb571c9d78862115dfdc5dae1cf2a35343580
Change-Id: I7dc661863b73f4198ddb4f3a1566583d0f07db3c

core/java/android/net/DataUsageRequest.java

@@ -16,6 +16,7 @@
 
 package android.net;
 
+import android.annotation.Nullable;
 import android.net.NetworkTemplate;
 import android.os.Parcel;
 import android.os.Parcelable;
@@ -95,7 +96,7 @@ public final class DataUsageRequest implements Parcelable {
     }
 
     @Override
-    public boolean equals(Object obj) {
+    public boolean equals(@Nullable Object obj) {
         if (obj instanceof DataUsageRequest == false) return false;
         DataUsageRequest that = (DataUsageRequest) obj;
         return that.requestId == this.requestId

core/java/android/net/IpSecTransform.java

@@ -19,6 +19,7 @@ import static android.net.IpSecManager.INVALID_RESOURCE_ID;
 
 import android.annotation.IntDef;
 import android.annotation.NonNull;
+import android.annotation.Nullable;
 import android.annotation.RequiresFeature;
 import android.annotation.RequiresPermission;
 import android.annotation.SystemApi;
@@ -150,7 +151,7 @@ public final class IpSecTransform implements AutoCloseable {
     /**
      * Standard equals.
      */
-    public boolean equals(Object other) {
+    public boolean equals(@Nullable Object other) {
         if (this == other) return true;
         if (!(other instanceof IpSecTransform)) return false;
         final IpSecTransform rhs = (IpSecTransform) other;

core/java/android/net/NetworkIdentity.java

@@ -18,6 +18,7 @@ package android.net;
 
 import static android.net.ConnectivityManager.TYPE_WIFI;
 
+import android.annotation.Nullable;
 import android.content.Context;
 import android.net.wifi.WifiInfo;
 import android.net.wifi.WifiManager;
@@ -67,7 +68,7 @@ public class NetworkIdentity implements Comparable<NetworkIdentity> {
     }
 
     @Override
-    public boolean equals(Object obj) {
+    public boolean equals(@Nullable Object obj) {
         if (obj instanceof NetworkIdentity) {
             final NetworkIdentity ident = (NetworkIdentity) obj;
             return mType == ident.mType && mSubType == ident.mSubType && mRoaming == ident.mRoaming

core/java/android/net/NetworkStats.java

@@ -412,7 +412,7 @@ public final class NetworkStats implements Parcelable {
 
         /** @hide */
         @Override
-        public boolean equals(Object o) {
+        public boolean equals(@Nullable Object o) {
             if (o instanceof Entry) {
                 final Entry e = (Entry) o;
                 return uid == e.uid && set == e.set && tag == e.tag && metered == e.metered

core/java/android/net/NetworkTemplate.java

@@ -329,7 +329,7 @@ public class NetworkTemplate implements Parcelable {
     }
 
     @Override
-    public boolean equals(Object obj) {
+    public boolean equals(@Nullable Object obj) {
         if (obj instanceof NetworkTemplate) {
             final NetworkTemplate other = (NetworkTemplate) obj;
             return mMatchRule == other.mMatchRule