-Move Android impl into interfaces_android.go
-Instead of using ip route to get the interface name, use the one passed in by Android (ip route is restricted in Android 13+ per termux/termux-app#2993)
Follow-up will be to do the same for router
Fixestailscale/corp#19215Fixestailscale/corp#19124
Signed-off-by: kari-ts <kari@tailscale.com>