[Android] Implement empty view for download manager ui

chrome/android/java/strings/android_chrome_strings.grd

 <?xml version="1.0" encoding="UTF-8"?>
 
 <!-- android_chrome_strings.grd contains strings for Chrome for Android.
 
 FAQ:
   - How do I add, change, or remove a string?
       Just update this file.
   - Translations will happen automatically??
       Yes, indeed. Just add your string before the branch point and
       make the description good.
@@ skipping 1783 matching lines @@
       </message>
       <message name="IDS_DOWNLOAD_MANAGER_UI_OTHER" desc="Indicates that clicking on this button shows any downloads that don't fit in the other categories.">
         Other
       </message>
       <message name="IDS_DOWNLOAD_PAGE" desc="Download this page.">
         Download page
       </message>
       <message name="IDS_DOWNLOAD_MANAGER_UI_DELETED" desc="Indicates that a downloaded file has been deleted.">
         Deleted
       </message>
+      <message name="IDS_DOWNLOAD_MANAGER_UI_EMPTY" desc="Indicates that there are no downloaded items.">
+        No downloads here
+      </message>
 
       <!-- Document mode messages -->
       <message name="IDS_CLOSE_ALL_INCOGNITO_NOTIFICATION" desc="Message on the notification that closes all incognito tabs in document mode">
         Close all incognito tabs
       </message>
 
       <!-- Autofill/Wallet integration prompt -->
       <message name="IDS_CARD_UNMASK_INPUT_HINT" desc="Hint text for an input field containing the user's credit card CVC (card verification code).">
         CVC
       </message>
@@ skipping 791 matching lines @@
         Tap this button for quick access to your tabs.
       </message>
 
       <!-- Item Chooser UI strings -->
       <message name="IDS_ITEM_CHOOSER_ITEM_NAME_WITH_ID" desc="To distinguish items with the same name, the item chooser shows the item name with id.">
         <ph name="ITEM_NAME">%1$s<ex>item_name</ex></ph> (<ph name="ITEM_ID">%2$s<ex>item id</ex></ph>)
       </message>
     </messages>
   </release>
 </grit>