HBASE-25165 Change 'State time' in UI so sorts (#2508)

Display startcode in iso8601.

Signed-off-by: Nick Dimiduk <ndimiduk@apache.org>

hbase-server/src/main/jamon/org/apache/hadoop/hbase/tmpl/master/RegionServerListTmpl.jamon

@@ -121,7 +121,7 @@ Arrays.sort(serverNames);
 </%java>
 <tr>
     <td><& serverNameLink; serverName=serverName; &></td>
-    <td><% new Date(startcode) %></td>
+    <td><% java.time.Instant.ofEpochMilli(startcode) %></td>
     <td><% TraditionalBinaryPrefix.long2String(lastContact, "s", 1) %></td>
     <td><% version %></td>
     <td><% String.format("%,.0f", requestsPerSecond) %></td>