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:

<edit-config file="app/src/main/AndroidManifest.xml" target="/manifest/application/activity" mode="merge">
    <activity android:exported="true"/>

<edit-config file="app/src/main/AndroidManifest.xml" target="/manifest/application/service" mode="merge">
    <service android:exported="true" />

<edit-config file="app/src/main/AndroidManifest.xml" target="/manifest/application/provider" mode="merge">
    <provider android:exported="true" />

<edit-config file="app/src/main/AndroidManifest.xml" target="/manifest/application/receiver" mode="merge">
    <receiver android:exported="true" />

But be carefully, 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.