docs: Added 'community' and 'bug report' links

Added both links to the landing page, and fixed the 'community' link
for the 'overview' and 'support' pages.

See first comment for doc stage locations.

bug: 21371878
Change-Id: I0c650008e11dccfe036177420511d5ee856cf125

docs/html/preview/index.jd

@@ -1,5 +1,5 @@
 page.title=Android M Developer Preview
-page.tags="preview", 
+page.tags="preview",
 meta.tags="preview, M preview"
 fullpage=true
 section.landing=true
@@ -49,5 +49,19 @@ footer.hide=1
        data-cardSizes="6x6"
        data-initial-results="6"
        data-maxResults="16"></div>
+
+  <ul class="dac-section-links">
+    <li class="dac-section-link"><a href="http://g.co/dev/AndroidMDevPreview">
+      <span class="dac-sprite dac-auto-chevron"></span>
+      Join G+ Community
+    </a></li>
+
+    <li class="dac-section-link">
+      <a href="https://code.google.com/p/android-developer-preview/">
+        <span class="dac-sprite dac-auto-chevron"></span>
+        Report Issues
+      </a>
+    </li>
+  </ul>
 </div></section>
 

docs/html/preview/support.jd

@@ -11,7 +11,7 @@ page.image=images/cards/card-support_16-9_2x.png
 
 <p>
   For more support, join the
-  <a href="https://plus.google.com/communities/101985907812750684586">M Developer
+  <a href="http://g.co/dev/AndroidMDevPreview">M Developer
   Preview Google+ community</a> to discuss your development experiences.
 </p>