Add debug_app_runner_criticals command

It sets up gdbserver for app runner with fatal critical warnings.

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>
googleplay: don't set state of star rating to null

It produces critical warning - incompatible variant type for
GLib.Action.

Signed-off-by: Jiří Janoušek <janousek.jiri@gmail.com>