fix:minio operator should not use a fixed name while deployment.

[jiuker]

Now we will get deployment by a fixed name minio-operator. We should get it from env first.

// getOperatorDeploymentName Internal func returns the Operator deployment name from MINIO_OPERATOR_DEPLOYMENT_NAME ENV variable or the default name
func getOperatorDeploymentName() string {
	return env.Get(OperatorDeploymentNameEnv, DefaultDeploymentName)
}

[shtripat]

lgtm