NIFI-9054 Calling Nifi Registry's createExtensionBundleVersion REST endpoint will cause NullPointerException (#5309)

Co-authored-by: Robert Kalmar <rkalmar@cloudera.com>
diff --git a/nifi-registry/nifi-registry-core/nifi-registry-framework/src/main/java/org/apache/nifi/registry/service/extension/StandardExtensionService.java b/nifi-registry/nifi-registry-core/nifi-registry-framework/src/main/java/org/apache/nifi/registry/service/extension/StandardExtensionService.java
index 0dddbfc..eec9d86 100644
--- a/nifi-registry/nifi-registry-core/nifi-registry-framework/src/main/java/org/apache/nifi/registry/service/extension/StandardExtensionService.java
+++ b/nifi-registry/nifi-registry-core/nifi-registry-framework/src/main/java/org/apache/nifi/registry/service/extension/StandardExtensionService.java
@@ -333,10 +333,12 @@
             extensionEntity.setId(UUID.randomUUID().toString());
             extensionEntity.setBundleVersionId(versionEntity.getId());
 
-            extensionEntity.getRestrictions().forEach(r -> {
-                r.setId(UUID.randomUUID().toString());
-                r.setExtensionId(extensionEntity.getId());
-            });
+            if (extensionEntity.getRestrictions() != null) {
+                extensionEntity.getRestrictions().forEach(r -> {
+                    r.setId(UUID.randomUUID().toString());
+                    r.setExtensionId(extensionEntity.getId());
+                });
+            }
 
             extensionEntity.getProvidedServiceApis().forEach(p -> {
                 p.setId(UUID.randomUUID().toString());
diff --git a/nifi-registry/nifi-registry-core/nifi-registry-framework/src/main/java/org/apache/nifi/registry/service/mapper/ExtensionMappings.java b/nifi-registry/nifi-registry-core/nifi-registry-framework/src/main/java/org/apache/nifi/registry/service/mapper/ExtensionMappings.java
index c655951..0296e96 100644
--- a/nifi-registry/nifi-registry-core/nifi-registry-framework/src/main/java/org/apache/nifi/registry/service/mapper/ExtensionMappings.java
+++ b/nifi-registry/nifi-registry-core/nifi-registry-framework/src/main/java/org/apache/nifi/registry/service/mapper/ExtensionMappings.java
@@ -210,12 +210,10 @@
             entity.setProvidedServiceApis(Collections.emptySet());
         }
 
-        if (extension.getRestricted() != null) {
-            if (extension.getRestricted().getRestrictions() != null) {
-                entity.setRestrictions(extension.getRestricted().getRestrictions().stream()
-                        .map(r -> map(r))
-                        .collect(Collectors.toSet()));
-            }
+        if (extension.getRestricted() != null && extension.getRestricted().getRestrictions() != null) {
+            entity.setRestrictions(extension.getRestricted().getRestrictions().stream()
+                    .map(r -> map(r))
+                    .collect(Collectors.toSet()));
         } else {
             entity.setRestrictions(Collections.emptySet());
         }