Remove import ONC option from internet settings (to be moved to net-internals).

chrome/browser/resources/options/chromeos/internet_options.html

 <div id="internetPage" class="page" hidden>
   <h1 i18n-content="internetPage"></h1>
   <div id="locked-network-banner" hidden>
     <span id="locked-network-icon"></span>
     <span id="access-locked-text" i18n-content="accessLockedMsg"></span>
   </div>
   <div class="displaytable">
     <section id="wireless-buttons">
      <h3 i18n-content="generalNetworkingTitle"></h3>
      <div id="network-general-div">
@@ skipping 19 matching lines @@
          <span i18n-content="ownerUserId"></span>
        </div>
        <div id="data-roaming" class="checkbox">
          <label>
            <input id="enable-data-roaming" 
                pref="cros.signed.data_roaming_enabled"
                metric="Options_Internet_DataRoaming" type="checkbox">
            <span i18n-content="enableDataRoaming"></span>
          </label>
        </div>
-       <div id="import-network-settings">
-         <div i18n-content="importNetworkSettings"></div>
-         <input type="file" name="network_settings" id="upload-network-settings"/>
-       </div>
      </div>
     </section>
     <section id="wired-section">
       <h3 i18n-content="wired_title" class="network-title"></h3>
       <div id="wired-list" class="networks"></div>
     </section>
     <section id="wireless-section">
       <h3 i18n-content="wireless_title" class="network-title"></h3>
       <div id="wireless-list" class="networks"></div>
     </section>
     <section id="vpn-section">
       <h3 i18n-content="vpn_title" class="network-title"></h3>
       <div id="vpn-list" class="networks"></div>
     </section>
     <section id="remembered-section">
       <h3 i18n-content="remembered_title" class="network-title"></h3>
       <div id="remembered-list" class="networks"></div>
     </section>
   </div>
 </div>