Bug 1422376 - Buttons should be at top and not in the middle of the release notes r=mstriemer,aswan

Differential Revision: https://phabricator.services.mozilla.com/D15326

--HG--
extra : moz-landing-system : lando

toolkit/mozapps/extensions/content/extensions.xml

@@ -569,7 +569,7 @@
 
       <xul:image class="card-heading-image" anonid="theme-screenshot" xbl:inherits="src=previewURL"/>
 
-      <xul:hbox class="content-container" align="center">
+      <xul:hbox class="content-container">
         <xul:vbox class="icon-container">
           <xul:image anonid="icon" class="icon"/>
         </xul:vbox>

toolkit/themes/shared/extensions/extensions.inc.css

@@ -469,7 +469,11 @@ button.warning {
   -moz-box-align: center;
 }
 
-.content-container,
+.content-container {
+  -moz-box-align: center;
+}
+
+#updates-list > .addon > .content-container,
 .basicinfo-container {
   -moz-box-align: start;
 }