MD Settings: Fix subpage navigation focus for bluetooth+internet

ui/webui/resources/cr_elements/network/cr_network_list_item.html

 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/html/polymer.html">
+<link rel="import" href="chrome://resources/polymer/v1_0/iron-a11y-keys/iron-a11y-keys.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/iron-flex-layout/classes/iron-flex-layout.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button-light.html">
 <link rel="import" href="chrome://resources/cr_elements/network/cr_network_icon.html">
 <link rel="import" href="chrome://resources/cr_elements/network/cr_onc_types.html">
 <link rel="import" href="chrome://resources/cr_elements/policy/cr_policy_indicator.html">
 <link rel="import" href="chrome://resources/cr_elements/policy/cr_policy_network_behavior.html">
 <link rel="import" href="chrome://resources/cr_elements/shared_style_css.html">
 
 <dom-module id="cr-network-list-item">
   <template>
@@ skipping 67 matching lines @@
         </div>
       </div>
       <template is="dom-if" if="[[isPolicySource(networkState.Source)]]">
         <cr-policy-indicator
             indicator-type="[[getIndicatorTypeForSource(networkState.Source)]]">
         </cr-policy-indicator>
       </template>
       <template is="dom-if"
           if="[[isSubpageButtonVisible_(networkState, showButtons)]]">
         <div id="subpageDiv" class="layout horizontal">
+          <!-- iron-list captures 'enter' so handle it here explicitly. -->
+          <iron-a11y-keys keys="enter" on-keys-pressed="fireShowDetails_">
+          </iron-a11y-keys>
           <button class="subpage-arrow" is="paper-icon-button-light"
               on-tap="fireShowDetails_" tabindex$="[[tabindex]]"
               aria-label$="[[ariaLabel]]">
           </button>
         </div>
       </template>
     </div>
   </template>
   <script src="cr_network_list_item.js"></script>
 </dom-module>