Mark implicit PendingIntents as immutable

Bug: 156020795
Test: manual, atest
Change-Id: I72206c7a52b067b77d6542d170a6483713dfeee7
(cherry picked from commit 84e08280d3882cfe4bad12ab426016c6d0efc7fb)
(cherry picked from commit 599c3e4b75a638a725de1c96bab762cdaae9eb22)

Author: Steve Elliott

packages/SystemUI/src/com/android/systemui/util/leak/LeakReporter.java

@@ -104,9 +104,13 @@ public void dumpLeak(int garbageCount) {
                     .setContentText(String.format(
                             "SystemUI has detected %d leaked objects. Tap to send", garbageCount))
                     .setSmallIcon(com.android.internal.R.drawable.stat_sys_adb)
-                    .setContentIntent(PendingIntent.getActivityAsUser(mContext, 0,
+                    .setContentIntent(PendingIntent.getActivityAsUser(
+                            mContext,
+                            0,
                             getIntent(hprofFile, dumpFile),
-                            PendingIntent.FLAG_UPDATE_CURRENT, null, UserHandle.CURRENT));
+                            PendingIntent.FLAG_UPDATE_CURRENT | PendingIntent.FLAG_IMMUTABLE,
+                            null,
+                            UserHandle.CURRENT));
             notiMan.notify(TAG, 0, builder.build());
         } catch (IOException e) {
             Log.e(TAG, "Couldn't dump heap for leak", e);