Add back optional plugin and tweak required plugins to undo merge changes

Author: Aaron Caldwell

x-pack/plugins/triggers_actions_ui/kibana.json

@@ -3,7 +3,8 @@
   "version": "kibana",
   "server": true,
   "ui": true,
-  "requiredPlugins": ["management", "charts", "data", "kibanaReact", "savedObjects", "features"],
+  "optionalPlugins": ["alerts", "features", "home"],
+  "requiredPlugins": ["management", "charts", "data", "kibanaReact", "savedObjects"],
   "configPath": ["xpack", "trigger_actions_ui"],
   "extraPublicDirs": ["public/common", "public/common/constants"],
   "requiredBundles": ["home", "alerts", "esUiShared", "kibanaReact", "kibanaUtils"]