init: Export Android version from kernel command line

This flag will be provided by our flasher to facilitate support for both
Android 11 and 12 in the same kernel.

Signed-off-by: Danny Lin <danny@kdrag0n.dev>
[fiqri19102002: Set default Android version to 11]
Signed-off-by: Fiqri Ardyansyah <fiqri15072019@gmail.com>
Signed-off-by: fajar <santuyz321@gmail.com>