Google released a new feature that adds a string of metadata to all APK files when the developer signs them; it is a DRM system that prevents installing an application that has not been signed during its final compilation.
Google implements a DRM system for Android applications
The concept of DRM is nothing new, in fact, it has been and is a great burden in PC games, which are plagued by DRM systems that often involve problems, which are not suffered by those users who choose to play the pirated version of the game, it is ironic that those who pay to get a worse experience.
In this case, DRM is a way for a developer or publisher to track software versions and authenticity. One reason is correct, but there is a concern that Google will one day begin to limit how, where, when and why we can use the applications we pay for.
Android can read the metadata that is automatically inserted into an application and verify that it is a legitimate version and that the developer has approved its use, if you pass these controls, it is added to the Google Play Store library. The developer can change the metadata at any time with a new signature key, which ends the support for the current version and creates a new list on Google Play.
Google says it did this to allow developers more control over how their applications are used and allow applications to be shared using peer-to-peer distribution channels. Hopefully, it does not end up hurting the experience of using the apps.