Make sure to pass the change info to file-list header extensions

Some extensions rely on this information to determine whether or not to show
columns. This needs to be consistent across the column header and column-rows
themselves.

Release-Notes: skip
Change-Id: I7325fb196560a42fd4cf222f8de00840d9f8d96e
diff --git a/polygerrit-ui/app/elements/change/gr-file-list/gr-file-list.ts b/polygerrit-ui/app/elements/change/gr-file-list/gr-file-list.ts
index abb637c..3779619 100644
--- a/polygerrit-ui/app/elements/change/gr-file-list/gr-file-list.ts
+++ b/polygerrit-ui/app/elements/change/gr-file-list/gr-file-list.ts
@@ -1012,7 +1012,10 @@
           class="extra-col"
           .name=${headerEndpoint}
           role="columnheader"
-        ></gr-endpoint-decorator>
+        >
+          <gr-endpoint-param name="change" .value=${this.change}>
+          </gr-endpoint-param>
+        </gr-endpoint-decorator>
       `
     );
   }