Add FLAG_IMMUTABLE to PendingIntents

If your app targets Android 12, you must specify the mutability of each
PendingIntent object that your app creates. This additional requirement
improves your app's security.
https://developer.android.com/about/versions/12/behavior-changes-12#pending-intent-mutability

Android Lint is being updated, and adds an error-level check for this.

Bug: 247885568
Test: Presubmits
Change-Id: I0634a7cf0c05e69f66c882158eb5f3fd1431bb7e
diff --git a/src/com/android/settings/intelligence/suggestions/model/CandidateSuggestion.java b/src/com/android/settings/intelligence/suggestions/model/CandidateSuggestion.java
index 2502e2a..c04e7d4 100644
--- a/src/com/android/settings/intelligence/suggestions/model/CandidateSuggestion.java
+++ b/src/com/android/settings/intelligence/suggestions/model/CandidateSuggestion.java
@@ -230,8 +230,8 @@
                 .setSummary(summary)
                 .setFlags(flags)
                 .setIcon(icon)
-                .setPendingIntent(PendingIntent
-                        .getActivity(mContext, 0 /* requestCode */, mIntent, 0 /* flags */));
+                .setPendingIntent(PendingIntent.getActivity(
+                        mContext, 0 /* requestCode */, mIntent, PendingIntent.FLAG_IMMUTABLE));
     }
 
     /**