Enable policy support for registering protocol handler.

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 184 matching lines @@
     <message name="IDS_POLICY_NETWORK_CONFIG_IMPORT_PARTIAL" desc="The text displayed in the status column when the corresponding network configuration policy is not standard conform and was imported partially.">
       The network configuration doesn't comply to the ONC standard. Parts of the configuration may not be imported.
     </message>
     <message name="IDS_POLICY_NETWORK_CONFIG_IMPORT_FAILED" desc="The text displayed in the status column when the corresponding network configuration policy is invalid.">
       The network configuration is invalid and couldn't be imported.
     </message>
     <message name="IDS_POLICY_SCOPE_ERROR" desc="Text displayed in the status column when a policy is set in an unsupported scope.">
       Policy scope is not supported.
     </message>
   </if>
+  <message name="IDS_POLICY_LEVEL_ERROR" desc="Text displayed in the status column when a policy is set at an unsupported level.">
+    Policy level is not supported.
+  </message>
   <message name="IDS_POLICY_OK" desc="Text displayed in the status column when a valid value is set for a policy.">
     OK
   </message>
   <message name="IDS_POLICY_UNSET" desc="Text displayed in the status column when no value is set for a policy.">
     Not set.
   </message>
   <message name="IDS_POLICY_UNKNOWN" desc="Text displayed in the status column when a policy name is not recognized.">
     Unknown policy.
   </message>
 
@@ skipping 80 matching lines @@
   <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>
 </grit-part>