Normally I can reinstall (preserving application data) APK only when it's signature matches the previous one.
How do I force upgrading of the application signed with a different key (for example, from a distribution version to a self-compiled version, for example) without removal of the data (i.e. uninstallation) using root access?
Workaround is backup application's data + uninstall + install + restore data, but that is inconvenient and notifies other applications about [un]installation which is not intended.
Ideally this should be a one-off exception that I personally approve, not just disabling of the whole signature verification mechanism.