[MD settings] explain when no usb devices are shown in site settings

chrome/app/settings_strings.grdp

Index: chrome/app/settings_strings.grdp
diff --git a/chrome/app/settings_strings.grdp b/chrome/app/settings_strings.grdp
index b9bda0bef12b5d478d38d00a1d29b8a6f09ea572..bad4dccba2effa9cd55555344019a685c102897e 100644
--- a/chrome/app/settings_strings.grdp
+++ b/chrome/app/settings_strings.grdp
@@ -933,7 +933,7 @@
     <message name="IDS_SETTINGS_PRINTING_CUPS_PRINTER_ADVANCED_URI" desc="Label for the CUPS printer URI (uniform resource identifier) in the Advanced section in the printer details page.">
       URI
     </message>
-    <message name="IDS_SETTINGS_PRINTING_CUPS_PRINTER_DETAILS_NAME" desc="Lable for the CUPS printer name in the printer details page.">
+    <message name="IDS_SETTINGS_PRINTING_CUPS_PRINTER_DETAILS_NAME" desc="Label for the CUPS printer name in the printer details page.">
       Name
     </message>
     <message name="IDS_SETTINGS_PRINTING_CUPS_PRINTER_DETAILS_MODEL" desc="Label for the CUPS printer model in the printer details page.">
@@ -2194,10 +2194,13 @@
   <message name="IDS_SETTINGS_SITE_DETAILS" desc="A title for the site settings details subpage.">
     Site details
   </message>
-  <message name="IDS_SETTINGS_SITE_NO_SITES_ADDED" desc="Explenation for not showing a list of site exceptions">
+  <message name="IDS_SETTINGS_SITE_NO_SITES_ADDED" desc="Explanation for not showing a list of site exceptions">
     No sites added
   </message>
 
+  <message name="IDS_SETTINGS_NO_USB_DEVICES_FOUND" desc="Explanation for not showing USB devices in site settings.">
+    No USB devices found
+  </message>
   <message name="IDS_SETTINGS_ADD_SITE_EXCEPTION_PLACEHOLDER" desc="Placeholder text shown before the user starts typing a new content settings exception for a site." >
     [*.]example.com
   </message>