There are new requirements for publishing apps in the google playstore. You have to set activitys, services, providers and receivers in your manifest to exported = true.
In ionic and cordova apps you can easly add this in your config.xml android section:
But be careful, you must remove unused sections or you can't build a release. This means if you are not using services and providers within your manifest, you have to remove the edit merge config shown above from your config.xml.