Add a mutability flag to the PendingIntent

It's soon going to be required for apps targeting S+ to specify
explicitly either FLAG_MUTABLE or FLAG_IMMUTABLE when creating
a PendingIntent. Thus, add a mutability flag to the
PendingIntent that doesn't specify it before.

Bug: 170602021
Bug: 170766590
Test: atest FrameworksNetTests
Change-Id: I56581033c0a1b450b6626112cdae5e5d9aac873f
diff --git a/services/core/java/com/android/server/connectivity/LingerMonitor.java b/services/core/java/com/android/server/connectivity/LingerMonitor.java
index 04c000f..7fdc7a0 100644
--- a/services/core/java/com/android/server/connectivity/LingerMonitor.java
+++ b/services/core/java/com/android/server/connectivity/LingerMonitor.java
@@ -159,8 +159,9 @@
 
     @VisibleForTesting
     protected PendingIntent createNotificationIntent() {
-        return PendingIntent.getActivityAsUser(mContext, 0, CELLULAR_SETTINGS,
-                PendingIntent.FLAG_CANCEL_CURRENT, null, UserHandle.CURRENT);
+        return PendingIntent.getActivityAsUser(mContext, 0 /* requestCode */, CELLULAR_SETTINGS,
+                PendingIntent.FLAG_CANCEL_CURRENT | PendingIntent.FLAG_IMMUTABLE,
+                null /* options */, UserHandle.CURRENT);
     }
 
     // Removes any notification that was put up as a result of switching to nai.
diff --git a/services/core/java/com/android/server/connectivity/NetworkNotificationManager.java b/services/core/java/com/android/server/connectivity/NetworkNotificationManager.java
index 34b0aa2..26356b4 100644
--- a/services/core/java/com/android/server/connectivity/NetworkNotificationManager.java
+++ b/services/core/java/com/android/server/connectivity/NetworkNotificationManager.java
@@ -325,7 +325,8 @@
     public void setProvNotificationVisible(boolean visible, int id, String action) {
         if (visible) {
             Intent intent = new Intent(action);
-            PendingIntent pendingIntent = PendingIntent.getBroadcast(mContext, 0, intent, 0);
+            PendingIntent pendingIntent = PendingIntent.getBroadcast(
+                    mContext, 0 /* requestCode */, intent, PendingIntent.FLAG_IMMUTABLE);
             showNotification(id, NotificationType.SIGN_IN, null, null, pendingIntent, false);
         } else {
             clearNotification(id);