fix(kubernetes): teach deployManifest stages to handle label selectors with generateName

[dbyron-sf]

This fixes:

java.lang.NullPointerException: Cannot invoke "com.netflix.spinnaker.clouddriver.kubernetes.description.manifest.KubernetesManifest.getNamespace()" because "manifest" is null
	at com.netflix.spinnaker.clouddriver.kubernetes.op.OperationResult.addManifest(OperationResult.java:46)
	at com.netflix.spinnaker.clouddriver.kubernetes.op.handler.CanDeploy.deploy(CanDeploy.java:44)
	at com.netflix.spinnaker.clouddriver.kubernetes.op.manifest.KubernetesDeployManifestOperation.lambda$operate$3(KubernetesDeployManifestOperation.java:174)
	at java.base/java.util.ArrayList.forEach(ArrayList.java:1511)
	at com.netflix.spinnaker.clouddriver.kubernetes.op.manifest.KubernetesDeployManifestOperation.operate(KubernetesDeployManifestOperation.java:162)
	at com.netflix.spinnaker.clouddriver.kubernetes.op.manifest.KubernetesDeployManifestOperation.operate(KubernetesDeployManifestOperation.java:48)
	at com.netflix.spinnaker.clouddriver.orchestration.AtomicOperation$operate.call(Unknown Source)
	at com.netflix.spinnaker.clouddriver.orchestration.DefaultOrchestrationProcessor$_process_closure1$_closure2.doCall(DefaultOrchestrationProcessor.groovy:120)
	at com.netflix.spinnaker.clouddriver.orchestration.DefaultOrchestrationProcessor$_process_closure1$_closure2.doCall(DefaultOrchestrationProcessor.groovy)
	at jdk.internal.reflect.GeneratedMethodAccessor373.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:107)
	at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:323)
	at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:274)
	at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1035)
	at groovy.lang.Closure.call(Closure.java:412)
	at groovy.lang.Closure.call(Closure.java:406)
	at com.netflix.spinnaker.clouddriver.metrics.TimedCallable$CallableWrapper.call(TimedCallable.java:81)
	at com.netflix.spinnaker.clouddriver.metrics.TimedCallable.call(TimedCallable.java:45)
	at java_util_concurrent_Callable$call.call(Unknown Source)
	at com.netflix.spinnaker.clouddriver.orchestration.DefaultOrchestrationProcessor$_process_closure1.doCall(DefaultOrchestrationProcessor.groovy:119)
	at com.netflix.spinnaker.clouddriver.orchestration.DefaultOrchestrationProcessor$_process_closure1.doCall(DefaultOrchestrationProcessor.groovy)
	at jdk.internal.reflect.GeneratedMethodAccessor367.invoke(Unknown Source)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:568)
	at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:107)
	at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:323)
	at org.codehaus.groovy.runtime.metaclass.ClosureMetaClass.invokeMethod(ClosureMetaClass.java:274)
	at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1035)
	at groovy.lang.Closure.call(Closure.java:412)
	at groovy.lang.Closure.call(Closure.java:406)
	at com.netflix.spinnaker.security.AuthenticatedRequest.lambda$wrapCallableForPrincipal$0(AuthenticatedRequest.java:272)
	at com.netflix.spinnaker.clouddriver.metrics.TimedCallable.call(TimedCallable.java:45)
	at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
	at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
	at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
	at java.base/java.lang.Thread.run(Thread.java:840)