Bug 1148677 - Use larger shareplane icon. r=liuche

We use a larger icon so that the icon is not blurry in the long-press context
menu.

Also, changed the name to icon_shareplane because it better represents that
this asset is extra-large and intended to be scaled because it's used as an
application icon.

--HG--
extra : rebase_source : 6ac8cb91b80047821e78af3d005d8049e9b23dfd

mobile/android/base/widget/ActivityChooserModel.java

@@ -783,7 +783,7 @@ public class ActivityChooserModel extends DataSetObservable {
                     }
 
                     resolveInfo.labelRes = R.string.overlay_share_send_other;
-                    resolveInfo.icon = R.drawable.share_plane;
+                    resolveInfo.icon = R.drawable.icon_shareplane;
                 }
 
                 mActivities.add(new ActivityResolveInfo(resolveInfo));