refactor: encapsulate Boolean conversion logic

Author: metacosm

Diff for: operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/dependent/kubernetes/BooleanWithUndefined.java

@@ -4,5 +4,16 @@
  * A replacement for {@link Boolean}, which can't be used in annotations.
  */
 public enum BooleanWithUndefined {
-  TRUE, FALSE, UNDEFINED
+  TRUE, FALSE, UNDEFINED;
+
+  Boolean asBoolean() {
+    switch (this) {
+      case TRUE:
+        return Boolean.TRUE;
+      case FALSE:
+        return Boolean.FALSE;
+      default:
+        return null;
+    }
+  }
 }

Diff for: operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/dependent/kubernetes/KubernetesDependentConverter.java

@@ -59,8 +59,7 @@ public KubernetesDependentResourceConfig<R> configFrom(KubernetesDependent confi
               context);
       createResourceOnlyIfNotExistingWithSSA =
           configAnnotation.createResourceOnlyIfNotExistingWithSSA();
-      useSSA = configAnnotation.useSSA() == BooleanWithUndefined.UNDEFINED ? null
-          : configAnnotation.useSSA() == BooleanWithUndefined.TRUE;
+      useSSA = configAnnotation.useSSA().asBoolean();
     }
 
     return new KubernetesDependentResourceConfig(namespaces, labelSelector, configuredNS,

Diff for: operator-framework-core/src/main/java/io/javaoperatorsdk/operator/processing/dependent/kubernetes/KubernetesDependentResource.java

@@ -190,7 +190,8 @@ protected void addMetadata(boolean forMatch, R actualResource, final R target, P
   }
 
   private boolean useSSA(Context<P> context) {
-    Optional<Boolean> useSSAConfig = configuration().flatMap(KubernetesDependentResourceConfig::useSSA);
+    Optional<Boolean> useSSAConfig =
+        configuration().flatMap(KubernetesDependentResourceConfig::useSSA);
     return useSSAConfig.orElse(context.getControllerConfiguration().getConfigurationService()
         .ssaBasedCreateUpdateMatchForDependentResources());
   }
@@ -207,6 +208,7 @@ public void deleteTargetResource(P primary, R resource, String key, Context<P> c
     client.resource(resource).delete();
   }
 
+  @SuppressWarnings("unused")
   protected Resource<R> prepare(R desired, P primary, String actionName) {
     log.debug("{} target resource with type: {}, with id: {}",
         actionName,