docs: better message for download page when os detection fails

Change-Id: I940c0847ddc214ef36bfd0708d289cff200dfc62
diff --git a/tools/droiddoc/templates-sdk/sdkpage.cs b/tools/droiddoc/templates-sdk/sdkpage.cs
index 17c1354..c0f3be7 100644
--- a/tools/droiddoc/templates-sdk/sdkpage.cs
+++ b/tools/droiddoc/templates-sdk/sdkpage.cs
@@ -210,11 +210,12 @@
   }
 
   if (os) {
-    $('#download-button').text("Download the SDK for " + os).removeClass("disabled");
+    $('#not-supported').hide();
+    $('#download-button').show();
+    $('#download-button').text("Download the SDK for " + os);
     $('#download-button').click(function() {onDownload($link.get());}).attr('href', $link.attr('href'));
   } else {
     $('.pax').show();
-    $('#download-button').css({'font-size':'14px'});
   }
 
 </script>