[Night Light] CL9: Add localization for time's AM and PM

chrome/app/settings_strings.grdp

 <?xml version="1.0" encoding="utf-8"?>
 <!-- Settings-specific strings (included from generated_resources.grd). -->
 <grit-part>
   <!-- Main Page -->
   <if expr="chromeos">
     <message name="IDS_SETTINGS_SECONDARY_USER_BANNER" desc="Banner displayed in settings page when the user is secondary in a multi-profile session.">
       Some settings belonging to <ph name="PRIMARY_EMAIL">$1<ex>john@google.com</ex></ph> are being shared with you. These settings only affect your account when using multiple sign-in.
     </message>
   </if>
 
@@ skipping 2965 matching lines @@
     </message>
     <message name="IDS_SETTINGS_DISPLAY_ARRANGEMENT_TEXT" desc="In Device Settings > Displays, text describing to use a mouse to drag the displays and change the arrangement.">
       Drag to move a display
     </message>
     <message name="IDS_SETTINGS_DISPLAY_MIRROR" desc="In Device Settings > Displays, the label for the control for mirroring.">
       Mirroring
     </message>
     <message name="IDS_SETTINGS_DISPLAY_NIGHT_LIGHT_LABEL" desc="In Device Settings > Displays, the label for the Night Light feature (which controls the color temperature of the screen) section.">
       Night Light
     </message>
+    <message name="IDS_SETTINGS_DISPLAY_NIGHT_LEGEND_6AM" desc="In Device Settings > Displays, the label of the time slider marker that marks the time 6 AM.">
+      6 AM
+    </message>
+    <message name="IDS_SETTINGS_DISPLAY_NIGHT_LEGEND_6PM" desc="In Device Settings > Displays, the label of the time slider marker that marks the time 6 pM.">
+      6 PM
+    </message>
+    <message name="IDS_SETTINGS_DISPLAY_NIGHT_LEGEND_12AM" desc="In Device Settings > Displays, the label of the time slider marker that marks the time 12 AM.">
+      12 AM
+    </message>
+    <message name="IDS_SETTINGS_DISPLAY_NIGHT_LEGEND_12PM" desc="In Device Settings > Displays, the label of the time slider marker that marks the time 12 PM.">
+      12 PM
+    </message>
     <message name="IDS_SETTINGS_DISPLAY_NIGHT_LIGHT_SCHEDULE_CUSTOM" desc="In Device Settings > Displays, the label of the option to set a custom schedule of the Night Light feature.">
       Custom Schedule
     </message>
     <message name="IDS_SETTINGS_DISPLAY_NIGHT_LIGHT_SCHEDULE_LABEL" desc="In Device Settings > Displays, the label for the automatic schedule section of the Night Light feature.">
       Schedule
     </message>
     <message name="IDS_SETTINGS_DISPLAY_NIGHT_LIGHT_SCHEDULE_NEVER" desc="In Device Settings > Displays, the label of the option to turn off the automatic schedule of the Night Light feature.">
       Never
     </message>
     <message name="IDS_SETTINGS_DISPLAY_NIGHT_LIGHT_SCHEDULE_SUNSET_TO_SUNRISE" desc="In Device Settings > Displays, the label of the option to set the automatic schedule of the Night Light feature to turn on at sunset and off at sunrise.">
@@ skipping 161 matching lines @@
       System
     </message>
     <message name="IDS_SETTINGS_SYSTEM_HARDWARE_ACCELERATION_LABEL" desc="Label for the checkbox that forces Chrome to render via hardware acceleration (GPU) when available.">
       Use hardware acceleration when available
     </message>
     <message name="IDS_SETTINGS_SYSTEM_PROXY_SETTINGS_LABEL" desc="Label for the control that opens a user's network proxy settings.">
       Open proxy settings
     </message>
   </if>
 </grit-part>