Center align button and label in revert dialog

Screenshot: https://imgur.com/a/IAoFKOP
Change-Id: I0ff4fa5d2c5e6455c5efe55ee1ee3ef5a3b04f31
diff --git a/polygerrit-ui/app/elements/change/gr-confirm-revert-dialog/gr-confirm-revert-dialog_html.ts b/polygerrit-ui/app/elements/change/gr-confirm-revert-dialog/gr-confirm-revert-dialog_html.ts
index 17647ad..3ec4f2c 100644
--- a/polygerrit-ui/app/elements/change/gr-confirm-revert-dialog/gr-confirm-revert-dialog_html.ts
+++ b/polygerrit-ui/app/elements/change/gr-confirm-revert-dialog/gr-confirm-revert-dialog_html.ts
@@ -32,10 +32,10 @@
     }
     .revertSubmissionLayout {
       display: flex;
+      align-items: center;
     }
     .label {
       margin-left: var(--spacing-m);
-      margin-bottom: var(--spacing-m);
     }
     iron-autogrow-textarea {
       font-family: var(--monospace-font-family);
@@ -47,6 +47,9 @@
       color: var(--error-text-color);
       margin-bottom: var(--spacing-m);
     }
+    label[for='messageInput'] {
+      margin-top: var(--spacing-m);
+    }
   </style>
   <gr-dialog
     confirm-label="Revert"