[FIXED JENKINS-34370] Fix NPE getting size of parameterDefinitions.size (#2296)

* Fix NPE getting size of parameterDefinitions.size

* Protect get against NPE

* readResolve and adequate List management

* [JENKINS-34370] Simplify code

* Address comments

* Address comments

* Use NullPointerException

core/src/main/java/hudson/model/ParametersDefinitionProperty.java

@@ -69,12 +69,22 @@ public class ParametersDefinitionProperty extends OptionalJobProperty<Job<?, ?>>
     private final List<ParameterDefinition> parameterDefinitions;
 
     @DataBoundConstructor
-    public ParametersDefinitionProperty(List<ParameterDefinition> parameterDefinitions) {
+    public ParametersDefinitionProperty(@Nonnull List<ParameterDefinition> parameterDefinitions) {
+        if (parameterDefinitions == null) {
+            throw new NullPointerException("ParameterDefinitions is null when this is a not valid value");
+        }
         this.parameterDefinitions = parameterDefinitions;
     }
 
-    public ParametersDefinitionProperty(ParameterDefinition... parameterDefinitions) {
-        this.parameterDefinitions = Arrays.asList(parameterDefinitions);
+    public ParametersDefinitionProperty(@Nonnull ParameterDefinition... parameterDefinitions) {
+        if (parameterDefinitions == null) {
+            throw new NullPointerException("ParameterDefinitions is null when this is a not valid value");
+        }
+        this.parameterDefinitions = Arrays.asList(parameterDefinitions) ;
+    }
+
+    private Object readResolve() {
+        return parameterDefinitions == null ? new ParametersDefinitionProperty() : this;
     }
 
     @Deprecated