docs: Fixed bad link to cloud-backup training class

The name and URL of the old "Syncing to the Cloud" class had changed.
Fixed a single bad link; also changed the title on other pages where
the class was referred to by the old name.

I know that changing the _toc.cs files is redundant at this point
(since we don't use those files to generate TOCs any more) but I
figured I'd do it for consistency's sake.

See first comment for doc stage location.

bug: 30309375
Change-Id: I0cd8b1442ef3a8dd8a1917e897a3f0555c48e6ef

docs/html/_redirects.yaml

@@ -421,6 +421,8 @@ redirects:
   to: /training/implementing-navigation/lateral.html
 - from: /training/cloudsync/aesync.html
   to: /google/gcm/index.html
+- from: /training/cloudsync/index.html
+  to: /training/backup/index.html
 - from: /training/basics/location/
   to: /training/location/
 - from: /training/monetization/index.html

docs/html/guide/topics/data/index.jd

@@ -11,13 +11,15 @@ page.landing.image=
   <div class="col-12">
     <h3>Training</h3>
 
-    <a href="http://developer.android.com/training/cloudsync/index.html">
-      <h4>Syncing to the Cloud</h4>
-      <p>This class covers different strategies for cloud enabled applications. It covers syncing
-data with the cloud using your own back-end web application, and backing up data using the cloud so
-that users can restore their data when installing your application on a new device.</p>
+    <a href="{@docRoot}training/backup/index.html">
+      <h4>Backing up App Data to the Cloud</h4>
+      <p>
+        This class covers techniques for backing up data to the cloud so that
+        users can restore their data when recovering from a data loss (such as a
+        factory reset) or installing your application on a new device.
+      </p>
     </a>
 
   </div>
 
-</div>
+</div>

docs/html/topic/performance/performance_toc.cs

@@ -656,7 +656,7 @@
              description=
              "How to sync and back up app and user data to remote web services in the
               cloud and how to restore the data back to multiple devices."
-            >Syncing to the Cloud</a>
+            >Backing up App Data to the Cloud</a>
         </div>
         <ul>
           <li><a href="<?cs var:toroot ?>training/backup/autosyncapi.html">

docs/html/training/_book.yaml

@@ -436,7 +436,7 @@ toc:
       path: /training/efficient-downloads/redundant_redundant.html
     - title: Modifying Patterns Based on the Connectivity Type
       path: /training/efficient-downloads/connectivity_patterns.html
-  - title: Syncing to the Cloud
+  - title: Backing up App Data to the Cloud
     path: /training/backup/index.html
     path_attributes:
     - name: description

docs/html/training/backup/backupapi.jd

@@ -1,5 +1,5 @@
 page.title=Using the Backup API
-parent.title=Syncing to the Cloud
+parent.title=Backing up App Data to the Cloud
 parent.link=index.html
 
 trainingnavtop=true

docs/html/training/training_toc.cs

@@ -656,7 +656,7 @@
              description=
              "How to sync and back up app and user data to remote web services in the
               cloud and how to restore the data back to multiple devices."
-            >Syncing to the Cloud</a>
+            >Backing up App Data to the Cloud</a>
         </div>
         <ul>
           <li><a href="<?cs var:toroot ?>training/backup/autosyncapi.html">