[WebLayer] Move Site Settings UI strings referenced by Java to components/browser_ui

This CL moves all strings referenced by Clank's Site Settings UI to
//components/browser_ui in preparation for moving the entire
site_settings package to that component.

Bug: 1058595
Change-Id: Iaa14adec41f5db6734a5692f0de486e6114d2eb6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2155396
Commit-Queue: Robbie McElrath <rmcelrath@chromium.org>
Reviewed-by: Finnur Thorarinsson <finnur@chromium.org>
Reviewed-by: Theresa  <twellington@chromium.org>
Cr-Commit-Position: refs/heads/master@{#762051}

components/browser_ui/strings/android/OWNERS

+# Please ensure you check for duplicate strings before adding new ones.
+#
+# Prefer generalizing feature specific existing strings instead of creating
+# a new version of the same (or an extremely similiar string).
+
+*

components/browser_ui/strings/android/browser_ui_strings.grd

@@ -168,6 +168,8 @@
   </translations>
   <release allow_pseudo="false" seq="1">
     <messages fallback_to_english="true">
+      <part file="site_settings.grdp" />
+
       <message name="IDS_DELETED" desc='Text that announces to the user that something was deleted.'>
         Deleted
       </message>