docs: fix platform highlights

Change-Id: I876a78661f2198eb8992f0183736de454cd2c4bc

Author: Robert Ly

docs/html/sdk/android-4.0.jd

@@ -72,7 +72,12 @@ class="toggle-content-img" alt="" />
   <div class="toggle-content-toggleme" style="padding-left:2em;">
 
 <dl>
-<dt>Initial release. SDK Tools r14 or higher is recommended.</dt>
+<dt>Initial release. SDK Tools r14 or higher is required.
+  <p class="caution"><strong>Important:</strong> To download the new Android
+  4.0 system components from the Android SDK Manager, you must first update the
+  SDK tools to revision 14 and restart the Android SDK Manager. If you do not,
+  the Android 4.0 system components will not be available for download.</p>
+</dt>
 </dl>
 
   </div>