Make the egress MITM gateway the default gateway

[haiyanmeng]

Currently, the MITM gateway is gated by an installation flag --experimental-use-sdsmint.

We plan to turn on MITM gateway by default and remove the flag.

The first step is to identify the blockers for turning on MITM gateway by default.

cc Bowei Du (@bowei) Lior Lieberman (@LiorLieberman)

[haiyanmeng]

Keith Mattix II (@keithmattix) , IIUC, you mentioned that one blocker is to figure out how to handle raw-TCP traffic like SSH in the OSS meeting today. Right?