accessibility fixes and minor css changes.

- added aria-hidden = "true" to prevent icons to be read by screen readers
- moved code on pages into "page-header" for better consistency

Change-Id: I3f497b2707991f7f628892a05734eea183a0d01d
Signed-off-by: Michael Davis <michael.s.davis@ibm.com>
diff --git a/app/server-health/controllers/unit-id-controller.html b/app/server-health/controllers/unit-id-controller.html
index 98b0bd5..23f5b1b 100644
--- a/app/server-health/controllers/unit-id-controller.html
+++ b/app/server-health/controllers/unit-id-controller.html
@@ -1,10 +1,9 @@
 <div id="uid-switch">
     <div class="row column">
         <h1>Server LED</h1>
-    </div>
-
-    <div class="row column">
-        <h2 class="h4">LED light control</h2>
+        <div class="page-header">
+            <h2 class="h4">LED light control</h2>
+        </div>
     </div>
 
     <div class="row column" ng-class="{disabled: dataService.server_unreachable || dataService.loading}">