consumer GenesisState.preCCV is hardcoded

[mpoke]

Problem

The preCCV flag in the genesis of the consumer CCV module should be set by the provider when handling a proposal to add a new consumer chain. See spec for more details.

As of https://github.com/cosmos/interchain-security/pull/757, where all changes only affect consumers, a sovereign to consumer changeover chain will have to query the provider for a genesis state, manually change that genesis JSON before it is used on consumer, then the consumer reads that file. See this code.

Closing criteria

The logic in the spec is implemented.