Adds background fade in animation and exit label to touch calibrator view

ui/strings/ui_strings.grd

 <?xml version="1.0" encoding="UTF-8"?>
 
 <!-- This file contains definitions of resources that will be translated for
 each locale. Specifically, these are UI strings that are used by app/ that
 need to be translated for each locale.-->
 
 <grit base_dir="." latest_public_release="0" current_release="1"
       output_all_resource_defines="false" source_lang_id="en" enc_check="möl">
   <outputs>
     <!-- TODO add each of your output files.  Modify the three below, and add
@@ skipping 638 matching lines @@
       </message>
       <message name="IDS_APP_LIST_FOLDER_CLOSE_FOLDER_ACCESSIBILE_NAME" desc="The spoken feedback text for closing an app launcher folder">
         Close folder
       </message>
       <message name="IDS_APP_LIST_SPEECH_HINT_TEXT" desc="The text label in the speech recognition UI to ask the user to speak the search query">
         Speak now
       </message>
       <message name="IDS_APP_LIST_SPEECH_NETWORK_ERROR_HINT_TEXT" desc="The text label in the speech recognition UI to show the speech recognition can't start because of network error.">
         No internet connection
       </message>
+
+      <!-- Strings describing the touch calibration UX -->
+      <message name="IDS_DISPLAY_TOUCH_CALIBRATION_EXIT_LABEL" desc="A message to notify the user about using the escape key to exit the calibration mode.">
+        To exit calibration press Esc.
+      </message>
       
       <!-- Display names -->
       <message name="IDS_DISPLAY_NAME_UNKNOWN" desc="The name used for a display whose name is unknown, which is shown in the display settings and ash tray.">
         Unknown Display
       </message>
       <message name="IDS_DISPLAY_NAME_INTERNAL" desc="The name used for internal displays, which is shown in the display settings.">
         Internal Display
       </message>
       <message name="IDS_DISPLAY_NAME_VIRTUAL" desc="The name used for virtual displays, which is shown in the display settings. Virtual displays are not associated with a physical monitor.">
         Virtual Display
       </message>
     </messages>
   </release>
 </grit>