[Policy] Remove unused strings in components

components/policy_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <grit-part>
 
   <message name="IDS_POLICY_DM_STATUS_SUCCESS" desc="Message indicating a successful device management server call.">
     Request succeeded
   </message>
   <message name="IDS_POLICY_DM_STATUS_REQUEST_INVALID" desc="Message indicating a bad request to the enterprise server.">
     Invalid request or request parameters
   </message>
   <message name="IDS_POLICY_DM_STATUS_REQUEST_FAILED" desc="Message indicating the request to the enterprise server failed in the network.">
@@ skipping 310 matching lines @@
     <message name="IDS_POLICY_SCOPE_DEVICE" desc="Mobile: Text displayed in the Applies To column when a policy applies to everyone on the device.">
       Device
     </message>
   </if>
   <message name="IDS_POLICY_LEVEL_RECOMMENDED" desc="Text displayed in the Level column when a policy is recommended.">
     Recommended
   </message>
   <message name="IDS_POLICY_LEVEL_MANDATORY" desc="Text displayed in the Level column when a policy is mandatory.">
     Mandatory
   </message>
-  <message name="IDS_POLICY_INVALID_BOOKMARK" desc="Text displayed in the status column when an entry of the ManagedBookmarks policy is not a valid bookmark.">
-    Ignored invalid bookmark at index <ph name="ENTRY_INDEX">$1<ex>3</ex></ph>
-  </message>
   <message name="IDS_POLICY_SOURCE_ENTERPRISE_DEFAULT" desc="Indicates that a policy is set by default in an enterprise environment and can be overridden (for Chrome OS only).">
     Enterprise default
   </message>
   <message name="IDS_POLICY_SOURCE_CLOUD" desc="Indicates that the policy originates from the cloud.">
     Cloud
   </message>
   <message name="IDS_POLICY_SOURCE_ACTIVE_DIRECTORY" desc="Indicates that the policy originates from Active Directory.">
     <ph name="MICROSOFT_ACTIVE_DIRECTORY">Microsoft® Active Directory®</ph>
   </message>
   <message name="IDS_POLICY_SOURCE_PLATFORM" desc="Indicates that the policy is obtained from the local OS.">
@@ skipping 17 matching lines @@
   <message name="IDS_POLICY_RISK_TAG_FILTERING" desc="Title of a group/tag whose policies might restrict web contents which would be visible otherwise (e.g. forced SafeSearch).">
     Filtering
   </message>
   <message name="IDS_POLICY_RISK_TAG_LOCAL_DATA_ACCESS" desc="Title of a group/tag whose policies might allow storage of user data to local drives where others might access them.">
     Local Data Access
   </message>
   <message name="IDS_POLICY_RISK_TAG_GOOGLE_SHARING" desc="Title of a group/tag whose policies enable functionality that might share user data with trusted Google services.">
     Sharing with Google
   </message>
 </grit-part>