Fix bug in warning activity intent.

Intents are no longer allowed to trigger without the NEW_TASK flag. This
old code path rotted and was never retrofitted to reflect this change.

By adding the flag in, this code path works again.

Bug: 122461924
Test: Manual
Change-Id: Idc825ebfedb795c02aefd61a202aefbea5bcd190
(cherry picked from commit a567233bca77f70b45a50f3972f00d1f0c6ce2c7)
diff --git a/src/com/android/storagemanager/automatic/NotificationController.java b/src/com/android/storagemanager/automatic/NotificationController.java
index 58c99d8..18e4533 100644
--- a/src/com/android/storagemanager/automatic/NotificationController.java
+++ b/src/com/android/storagemanager/automatic/NotificationController.java
@@ -98,12 +98,14 @@
     public void onReceive(Context context, Intent intent) {
         switch (intent.getAction()) {
             case INTENT_ACTION_ACTIVATE_ASM:
-                Settings.Secure.putInt(context.getContentResolver(),
+                Settings.Secure.putInt(
+                        context.getContentResolver(),
                         Settings.Secure.AUTOMATIC_STORAGE_MANAGER_ENABLED,
                         1);
                 // Provide a warning if storage manager is not defaulted on.
                 if (!SystemProperties.getBoolean(STORAGE_MANAGER_PROPERTY, false)) {
                     Intent warningIntent = new Intent(context, WarningDialogActivity.class);
+                    warningIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
                     context.startActivity(warningIntent);
                 }
                 break;