Show the image header for the Context Menu

chrome/android/java/strings/android_chrome_strings.grd

Index: chrome/android/java/strings/android_chrome_strings.grd
diff --git a/chrome/android/java/strings/android_chrome_strings.grd b/chrome/android/java/strings/android_chrome_strings.grd
index 2a3d16be546e4d542fc2aeb666e05c52a43f03c7..51c07d6da9da5fc4d6f094a6ed13cc2ade90d74f 100644
--- a/chrome/android/java/strings/android_chrome_strings.grd
+++ b/chrome/android/java/strings/android_chrome_strings.grd
@@ -2779,6 +2779,9 @@ You must have Bluetooth and Location turned on in order to use the Physical Web.
       <message name="IDS_CONTEXT_MENU_ROW_SHARE_ICON_DESCRIPTION" desc="The description of the icon next to the share menu item within a context menu.">
         An icon that represents the most recently used app when sharing in Chrome.
       </message>
+      <message name="IDS_CONTEXT_MENU_HEADER_IMAGE_DEFAULT_DESC_TEXT" desc="The image shown before a thumbnail loads within the context menu.">
+        A thumbnail of the image that was long pressed when accessing the context menu.
+      </message>
     </messages>
   </release>
 </grit>