Add strings for built-in U2F notification.

BUG=chromium:967396
TEST=None

Change-Id: Ic621fd170857a99c706bdc6f1e9987b71d1a3619
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1636349Reviewed-by: Dan Erat <derat@chromium.org>
Commit-Queue: Mattias Nissler <mnissler@chromium.org>
Cr-Commit-Position: refs/heads/master@{#664507}

chrome/app/chromeos_strings.grdp

@@ -2201,6 +2201,17 @@
     Reset your <ph name="DEVICE_TYPE">$1<ex>Chromebook</ex></ph> to upgrade your security.
   </message>
 
+  <!-- U2F Notification Strings -->
+  <message name="IDS_U2F_INSECURE_NOTIFICATION_TITLE" desc="Notification title shown to inform the user that the legacy U2F feature is insecure.">
+    Internal security key requires reset
+  </message>
+  <message name="IDS_U2F_INSECURE_NOTIFICATION_MESSAGE" desc="Notification shown to inform the user that the legacy U2F feature is insecure.">
+    Your internal security key is currently insecure. Please remove it from any services that you used it with. In order to resolve the issue, please reset the security key.
+  </message>
+  <message name="IDS_U2F_INSECURE_NOTIFICATION_RESET" desc="Label for the reset button in the notification shown to inform the user that the legacy U2F feature is insecure.">
+    Reset
+  </message>
+
   <!-- Obsolete versions Notification strings-->
   <message name="IDS_UPDATE_REQUIRED_LOGIN_SCREEN_MESSAGE" desc="The message on login screen to inform the user that policy prevents user sign in before OS version is is updated.">
     Your device is no longer compliant with the minimum client version specified by your admin. Please update to login.