Fix send button being disabled after dragging reviewers

Release-Notes: skip
Google-Bug-Id: b/448433596
Change-Id: I54d3abc3249c600c04e831f707ed1c310f7dfdb2
diff --git a/polygerrit-ui/app/elements/change/gr-reply-dialog/gr-reply-dialog.ts b/polygerrit-ui/app/elements/change/gr-reply-dialog/gr-reply-dialog.ts
index 623fe40..04c8618 100644
--- a/polygerrit-ui/app/elements/change/gr-reply-dialog/gr-reply-dialog.ts
+++ b/polygerrit-ui/app/elements/change/gr-reply-dialog/gr-reply-dialog.ts
@@ -1425,6 +1425,7 @@
       );
       if (!this.ccs.find(cc => getUserId(cc) === getUserId(accountToMove))) {
         this.ccs = [...this.ccs, accountToMove];
+        this.reviewersMutated = true;
       }
     } else {
       this.ccs = this.ccs.filter(
@@ -1434,6 +1435,7 @@
         !this.reviewers.find(r => getUserId(r) === getUserId(accountToMove))
       ) {
         this.reviewers = [...this.reviewers, accountToMove];
+        this.reviewersMutated = true;
       }
     }