Make PendingIntent immutable and correct Settings package name

ConnectivityService puts up some notifications with pending
intents, but these pending intents are mutable that content can
be changed by someone. So make these pending intents to be
immutable.

Some OEMs have their own Settings package. Thus, need to get the
current using Settings package name instead of just use default
name "com.android.settings".

Bug: 154928507
Test: atest FrameworksNetTests
Change-Id: I02e3277358623400aa03dc8996af3d7c46a8ce76
diff --git a/services/core/java/com/android/server/ConnectivityService.java b/services/core/java/com/android/server/ConnectivityService.java
index 2958fd2..2a1e54d 100644
--- a/services/core/java/com/android/server/ConnectivityService.java
+++ b/services/core/java/com/android/server/ConnectivityService.java
@@ -67,6 +67,7 @@
 import android.app.NotificationManager;
 import android.app.PendingIntent;
 import android.content.BroadcastReceiver;
+import android.content.ComponentName;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.Intent;
@@ -3069,7 +3070,11 @@
             // Only the system server can register notifications with package "android"
             final long token = Binder.clearCallingIdentity();
             try {
-                pendingIntent = PendingIntent.getBroadcast(mContext, 0, intent, 0);
+                pendingIntent = PendingIntent.getBroadcast(
+                        mContext,
+                        0 /* requestCode */,
+                        intent,
+                        PendingIntent.FLAG_IMMUTABLE);
             } finally {
                 Binder.restoreCallingIdentity(token);
             }
@@ -3925,6 +3930,15 @@
         pw.decreaseIndent();
     }
 
+    // TODO: This method is copied from TetheringNotificationUpdater. Should have a utility class to
+    // unify the method.
+    private static @NonNull String getSettingsPackageName(@NonNull final PackageManager pm) {
+        final Intent settingsIntent = new Intent(Settings.ACTION_SETTINGS);
+        final ComponentName settingsComponent = settingsIntent.resolveActivity(pm);
+        return settingsComponent != null
+                ? settingsComponent.getPackageName() : "com.android.settings";
+    }
+
     private void showNetworkNotification(NetworkAgentInfo nai, NotificationType type) {
         final String action;
         final boolean highPriority;
@@ -3959,12 +3973,20 @@
         if (type != NotificationType.PRIVATE_DNS_BROKEN) {
             intent.setData(Uri.fromParts("netId", Integer.toString(nai.network.netId), null));
             intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
-            intent.setClassName("com.android.settings",
-                    "com.android.settings.wifi.WifiNoInternetDialog");
+            // Some OEMs have their own Settings package. Thus, need to get the current using
+            // Settings package name instead of just use default name "com.android.settings".
+            final String settingsPkgName = getSettingsPackageName(mContext.getPackageManager());
+            intent.setClassName(settingsPkgName,
+                    settingsPkgName + ".wifi.WifiNoInternetDialog");
         }
 
         PendingIntent pendingIntent = PendingIntent.getActivityAsUser(
-                mContext, 0, intent, PendingIntent.FLAG_CANCEL_CURRENT, null, UserHandle.CURRENT);
+                mContext,
+                0 /* requestCode */,
+                intent,
+                PendingIntent.FLAG_CANCEL_CURRENT | PendingIntent.FLAG_IMMUTABLE,
+                null /* options */,
+                UserHandle.CURRENT);
 
         mNotifier.showNotification(nai.network.netId, type, nai, null, pendingIntent, highPriority);
     }