Doc: Update gallery screenshots

To match the updated example. Display a screenshot for both
Android and OS X in the gallery example documentation.

Change-Id: I37e56437bb54248a4d500810c56ce8a8ba15b4d2
Reviewed-by: J-P Nurmi <jpnurmi@theqtcompany.com>
Reviewed-by: Venugopal Shivashankar <venugopal.shivashankar@digia.com>
Reviewed-by: Martin Smith <martin.smith@digia.com>

src/controls/doc/src/qtquickcontrols-examples.qdoc

@@ -40,7 +40,22 @@
     \title Qt Quick Controls - Gallery
     \ingroup qtquickcontrols_examples
     \brief A collection of components for a classic desktop-style UI.
-    \image qtquickcontrols-example-gallery.png
+
+    \raw HTML
+    <div class="table"><table style="background:transparent; border:0px">
+    <tr><td style="border:0px">
+    \endraw
+    \image qtquickcontrols-example-gallery-osx.png
+    \caption OS X
+    \raw HTML
+    </td><td style="border:0px">
+    \endraw
+    \image qtquickcontrols-example-gallery-android.png
+    \caption Android - Nexus 5
+    \raw HTML
+    </td></tr>
+    </table></div>
+    \endraw
 
     This example project demonstrates the various UI components provided by
     \l{Qt Quick Controls}.

src/controls/doc/src/qtquickcontrols-platformnotes.qdoc

@@ -37,7 +37,7 @@
 
     Qt 5.4 introduced a native Android style for Qt Quick Controls.
 
-    \image qtquickcontrols-android.png
+    \image qtquickcontrols-example-gallery-android.png
 
     \note The Android style requires Android 3.0 (API level 11) or later.