I reported that bug to the ionic team and after the last recent update it is fixed.
In the meantime I updated to the last recent ionic cli (3.4.0) and the last recent cordova android platform (using this command: cordova platform update android@6.2.3 --save)
I cant figure out if perhaps one of that itself fixed the problem…
But now phonegap-plugin-push 1.10.4 is included in my apk file.