The purpose of this call is to initialize the Kusama side of the Polkadot<>Kusama bridge.
It does the following:
Calls forceXcmVersion on following system parachains to set XCMv3 between:
Kusama AH <-> Kusama BH
Kusama BH -> Polkadot BH
Kusama AH -> Polkadot AH
It then calls bridgePolkadotGrandpa::initialize() with the initial configuration for the Polkadot on-chain light-cLient running on Kusama Bridge Hub.
Whitelisted by: https://kusama.subsquare.io/fellowship/referenda/62
The initialize extrinsic to run on bridge hub ... we hope it works because it's not like the public can easily verify anything.