I'm developing a non google play application, that will be delivered as an unsigned release assembly apk to device manufacturers that will sign it with their own private system key signature.
the system signature is essential, because the app uses permissions with protection level signatureOrSystem .
since the app not going to be installed as a system privileged app, it must be signed with the system's signature.
since I'm not going to have access to the final signed apk (or the signing key itself) I don't know how can I test the product I'm delivering (on a real device and not emulator) since it functionality depends on been signed with a system signature.
so far, only reference I found is a very old thread discussing about how to sign with system signature, but as I understand - it will not work anymore.
I would like to understand what is the recommended work-flow for how to test my app behavior as it signed with a system signature on a real device.