fix: incorrect multiplication in provConsumerModifiedGenesis

[santamasa]

chainsuite.ProviderUnbondingTime is most likely a time.Duration, but it's being multiplied by 10000000 before converting to a string. This results in an incorrect value in the genesis config.

Instead of multiplying, it's better to use .Nanoseconds() to get the correct format:

Before:

cosmos.NewGenesisKV("app_state.staking.params.unbonding_time", (chainsuite.ProviderUnbondingTime * 10000000).String()),

After:

cosmos.NewGenesisKV("app_state.staking.params.unbonding_time", strconv.FormatInt(chainsuite.ProviderUnbondingTime.Nanoseconds(), 10)),

This ensures the unbonding time is correctly serialized in nanoseconds.