Environment property requires a . prefix.

This is a copy of PR https://github.com/spring-cloud/spring-cloud-deployer/pull/494/files
because it is not mergeable because the commit number has already been used.
i.e. it was pushed to main, then rolledback and git refuses to merge it again.

resolves 492

spring-cloud-deployer-kubernetes/src/main/java/org/springframework/cloud/deployer/spi/kubernetes/DeploymentPropertiesResolver.java

@@ -653,7 +653,7 @@ Collection<Container> getInitContainers(Map<String, String> kubernetesDeployerPr
 		if (StringUtils.hasText(containerName) && StringUtils.hasText(imageName)) {
 			String commandsStr = PropertyParserUtils.getDeploymentPropertyValue(kubeProps, propertyKey + ".commands");
 			List<String> commands = StringUtils.hasText(commandsStr) ? Arrays.asList(commandsStr.split(",")) : Collections.emptyList();
-			String envString = PropertyParserUtils.getDeploymentPropertyValue(kubeProps, propertyKey + "environmentVariables");
+			String envString = PropertyParserUtils.getDeploymentPropertyValue(kubeProps, propertyKey + ".environmentVariables");
 			List<VolumeMount> vms = this.getInitContainerVolumeMounts(kubeProps, propertyKey);
 			return new ContainerBuilder()
 					.withName(containerName)