Tweak BaseTestCase class

Now the interceptor registry is initialized via a protected method, thus
its type can be changed by overriding the method.

Change-Id: I146280f50517ec52d9f92c1f1fe19869b46538c7
Reviewed-on: https://bellevue-ci.eng.vmware.com:8080/46575
Closures-Verified: jenkins <[email protected]>
Upgrade-Verified: jenkins <[email protected]>
PG-Verified: jenkins <[email protected]>
Bellevue-Verified: jenkins <[email protected]>
CS-Verified: jenkins <[email protected]>
Reviewed-by: Sergio Sanchez <[email protected]>

common-test/src/test/java/com/vmware/admiral/common/test/BaseTestCase.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2016-2017 VMware, Inc. All Rights Reserved.
+ * Copyright (c) 2016-2018 VMware, Inc. All Rights Reserved.
  *
  * This product is licensed to you under the Apache License, Version 2.0 (the "License").
  * You may not use this product except in compliance with the License.
@@ -204,7 +204,7 @@ protected VerificationHost createHost(String[] args) throws Throwable {
 
     protected VerificationHost createHost(ServiceHost.Arguments args, String[] additionalArgs)
             throws Throwable {
-        OperationInterceptorRegistry interceptors = new OperationInterceptorRegistry();
+        OperationInterceptorRegistry interceptors = createInterceptorRegistry();
         registerInterceptors(interceptors);
 
         CustomizationVerificationHost customizationHost = new CustomizationVerificationHost(
@@ -233,7 +233,7 @@ protected Map.Entry<VerificationHost, ServerX509TrustManager> createHostWithTrus
             long reloadTime) throws Throwable {
         ServiceHost.Arguments args = getHostArguments();
 
-        OperationInterceptorRegistry interceptors = new OperationInterceptorRegistry();
+        OperationInterceptorRegistry interceptors = createInterceptorRegistry();
         registerInterceptors(interceptors);
 
         VerificationHost h = VerificationHost.initialize(
@@ -280,6 +280,10 @@ protected long getMaintenanceIntervalMillis() {
         return MAINTENANCE_INTERVAL_MILLIS;
     }
 
+    protected OperationInterceptorRegistry createInterceptorRegistry() {
+        return new OperationInterceptorRegistry();
+    }
+
     protected void registerInterceptors(OperationInterceptorRegistry registry) {
     }