[Feature request] Handle AFWall+ startup leak block on Android

[Atrate]

The most popular firewall for rooted Android devices has a feature that allows a user to block all network traffic through an init.d script before AFWall+ itself can start and apply rules, this prevents unauthorized apps' access to the Internet on startup.

Unfortunately, when MV tries to bring up last active tunnels at boot while network traffic is blocked, it will fail silently and stay not connected.

MV could check iptables for a global DROP chain if AFWall+ is detected and enter a wait loop until the condition is resolved through AFWall+ applying rules a few seconds after BOOT_COMPLETED.

The DROP chains: https://bin.privacytools.io/?419bee715e463d9a#+3FsHrk4ZEl3+eldPpLfnILtpjjpwdd15X/sAdjw8QA=

Original issue in another app based on WireGuard: msfjarvis/viscerion#156

Commit that implemented the feature in the aforementioned repo: msfjarvis/viscerion@f0b8a73