Amend success message spacing

The space between the "You've signed up to emails about this page"
message and the title below is too large

app/views/shared/_email_subscribe_unsubscribe_flash.html.erb

@@ -1,19 +1,20 @@
 <% if @account_flash.include?("email-subscription-success") %>
-  <div class="govuk-grid-row govuk-!-margin-top-7">
+  <div class="govuk-grid-row govuk-!-margin-top-3">
     <div class="govuk-grid-column-two-thirds">
       <%= render "govuk_publishing_components/components/success_alert", {
         message: sanitize(t("email.subscribe_title")),
-        description: sanitize(t("email.description_html"))
+        description: sanitize(t("email.description_html")),
+        margin_bottom: 0,
       } %>
     </div>
   </div>
-
 <% elsif @account_flash.include?("email-unsubscribe-success") %>
   <div class="govuk-grid-row">
-    <div class="govuk-grid-column-two-thirds govuk-!-margin-top-7">
+    <div class="govuk-grid-column-two-thirds govuk-!-margin-top-3">
       <%= render "govuk_publishing_components/components/success_alert", {
         message: sanitize(t("email.unsubscribe_title")),
-        description: sanitize(t("email.description_html"))
+        description: sanitize(t("email.description_html")),
+        margin_bottom: 0,
       } %>
     </div>
   </div>