Fix mobile app embedding display, which partially showed the content

- Width and height of the iframe now at 100%
- Container was always filling the content area but iframe was not, which was why this change was made

templates/mobile_view_page.mustache

 {{=<% %>=}}
 <div style="height: 100%; width: 100%; background: white;">
     <iframe
+            width="100%"
+            height="100%"
             src="<% wwwroot %>/mod/hvp/embed.php?id=<% cmid %>&user_id=<% user_id %>&secret=<% secret %>"
             frameborder="0"
             allow="microphone; camera"