[FIX] certik report minor issues

1.Move the number 17280 into constants.go 2.In validateUnstake reformat the check msg.UnstakeBasisPoints.GT(sdk.ZeroUint()) && msg.UnstakeBasisPoints.GT(...) as !msg.UnstakeBasisPoints.GT(sdk.ZeroUint()) || msg.UnstakeBasisPoints.GT(...) 3.vault_data.go • var amts []sdk.Uint: amts should be preallocated.