Add more detailed error message for unsupported SMB mounts

- Adds a message to provide users with a more detailed error message
  when SMB mounting to a file server that doesn't support SMBv2 or later.

Bug: chromium:887127
Change-Id: I9e2ff3c278bb014c5538082ddcba42c8556ba8f2
Reviewed-on: https://chromium-review.googlesource.com/c/1274608Reviewed-by: Zentaro Kavanagh <zentaro@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Commit-Queue: Bailey Berro <baileyberro@chromium.org>
Cr-Commit-Position: refs/heads/master@{#599353}

chrome/app/settings_strings.grdp

@@ -1442,7 +1442,7 @@
       Error mounting share. The specified share was not found on the network.
     </message>
     <message name="IDS_SETTINGS_DOWNLOADS_SHARE_ADDED_UNSUPPORTED_DEVICE_MESSAGE" desc="The message shown when mounting a new SMB share fails because the specified device is not supported.">
-      Error mounting share. The specified share is not supported.
+      Error mounting share. Please check that the file server you are connecting to supports SMBv2 or later.
     </message>
     <message name="IDS_SETTINGS_DOWNLOADS_SHARE_ADDED_MOUNT_EXISTS_MESSAGE" desc="The message shown when mounting a new SMB share fails because the share is already mounted.">
       Error mounting share. The specified share is already mounted.