fix: Change max size of panel JSON editor so button is shown on smaller screens, #10346 (#10415)

public/app/partials/edit_json.html

@@ -11,7 +11,7 @@
 
 	<div class="tabbed-view-body">
 		<div class="gf-form">
-			<code-editor content="json" data-mode="json" data-max-lines=40 ></code-editor>
+			<code-editor content="json" data-mode="json" data-max-lines=20 ></code-editor>
 		</div>
 
 		<div class="gf-form-button-row">