Fix closing and self-closing tags in templates

Void tags (e.g. <img>) couldn't have a closing tag (e.g. </img> is invalid). Non-void tags (e.g. <div>) couldn't be self closing (e.g. <div/> is invalid) and must be closed explicitly (e.g. with </div>). This CL fixes the tags which also prepares the templates for stricthtml which enforces it.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=168829028

java/google/registry/ui/soy/registrar/Contact.soy

@@ -103,7 +103,7 @@
                 {param namePrefix: 'contact:postalInfo[0].contact:' /}
               {/call}
             {/if}
-            <table id="domain-contact-postalInfos-footer"/>
+            <table id="domain-contact-postalInfos-footer"></table>
           </div>
         </td>
       </tr>