Add watchdog to AttachmentDownloadService

* Detect attachment downloads that have stalled and restart them
* Catch a couple of cases in which we weren't sending callbacks

Bug: 3122242

Change-Id: Id2bfd3b26182004b301cf8665f4feb6e62b98b73
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 4a99cb8..651aaa0 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -232,6 +232,9 @@
         <receiver android:name="com.android.exchange.MailboxAlarmReceiver"/>
         <!--EXCHANGE-REMOVE-SECTION-END-->
 
+        <receiver android:name=".service.AttachmentDownloadService$Watchdog"
+            android:enabled="true"/>
+
         <receiver android:name=".service.EmailBroadcastReceiver" android:enabled="true">
             <intent-filter>
                 <action android:name="android.intent.action.BOOT_COMPLETED" />