Fine tuned availability of hotword plugin.

chrome/app/chromeos_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- ChromeOS-specific strings (included from generated_resources.grd).
      Everything in this file is wrapped in <if expr="pp_ifdef('chromeos')">. -->
 <grit-part>
   <message name="IDS_EMPTY_STRING" desc="Empty string, exist only to make code generic. No translation required.">
   </message>
   <!-- Idle logout dialog for retail mode -->
   <message name="IDS_IDLE_LOGOUT_TITLE" desc="Dialog title for the idle logout dialog. Used in retail mode only.">
     Are you still there?
   </message>
@@ skipping 2433 matching lines @@
   </message>
   <message name="IDS_OPTIONS_SETTINGS_INTERNET_OPTIONS_LOGIN_FOR_USER_CERT" desc="In the network connect dialog, when creating a VPN or enterprise Wi-Fi connection, error message to display when not logged in and  user certificates are required.">
     Sign-in required for user certificate.
   </message>
   <message name="IDS_OPTIONS_SETTINGS_INTERNET_OPTIONS_REQUIRE_HARDWARE_BACKED" desc="In the network connect dialog, when creating a VPN or enterprise Wi-Fi connection, error message to display when a non hardware-backed user certificate is selected.">
     User certificate must be hardware-backed.
   </message>
   <message name="IDS_OPTIONS_ENABLE_CONTENT_PROTECTION_ATTESTATION" desc="description label for verified access about premium contents">
     Enable Verified Access service
   </message>
+  <message name="IDS_OPTIONS_ENABLE_HOTWORD_APP_LIST" desc="description label for the checkbox to enable/disable hotword in the app list search">
+    Enable "Ok, Google" to start a voice search in the app launcher.
+  </message>
   <message name="IDS_NETWORK_RECONNECT_TITLE" desc="In network menu, title of the reconnect button that allows user to retry connection on error.">
     Reconnect
   </message>
   <message name="IDS_NETWORK_SSID_HINT" desc="In network menu, hint text for network name field.">
     network name
   </message>
   <message name="IDS_NETWORK_PASSWORD_HINT" desc="In network menu, hint text for network password field.">
     network password
   </message>
 
@@ skipping 2477 matching lines @@
     We see that you've ordered a replacement charger.
   </message>
   <message name="IDS_CHARGER_REPLACEMENT_CHARGER_MORE_INFO" desc="Text for fining more info for charger">
     You can find more info at
   </message>
   <message name="IDS_CHARGER_REPLACEMENT_DIALOG_TITLE" desc="Title of the charger replacement UI dialg">
     Check charger
   </message>
 
 </grit-part>