Like I have said in the OP, I use the standard Android emulator from Android Studio. However, thanks for your answer but I can't accept an answer if it is not verified (I am kind of busy at the moment). I will try to verify it asap

Can someone confirm if this works? I am not able to test this in the next few weeks

It was more because of the fact that I never heard of that and was rather sceptical. But, and this is more important, I use the default emulator for a lot of things and I don't want to run a hundrets of emulators, each for different use cases...

This does not work. This error appears all the time: adb: error: failed to copy 'Phonesky.apk' to '/system/priv-app/Phonesky.apk': Read-only file system. No remount in any way does help, as the output of every remount is the following: mount: Read-only file system. Yeah, thanks android, thats why I want to remount it with rw -.-