adding rollback and system tags support (#323)

Author: ammokhov

src/main/java/software/amazon/cloudformation/AbstractWrapper.java

@@ -262,6 +262,10 @@ public void processRequest(final InputStream inputStream, final OutputStream out
             resourceHandlerRequest.setPreviousResourceTags(getPreviousResourceTags(request));
             resourceHandlerRequest.setStackId(getStackId(request));
             resourceHandlerRequest.setSnapshotRequested(request.getSnapshotRequested());
+            resourceHandlerRequest.setRollback(request.getRollback());
+            if (request.getRequestData() != null) {
+                resourceHandlerRequest.setPreviousSystemTags(request.getRequestData().getPreviousSystemTags());
+            }
         }
 
         this.metricsPublisherProxy.publishInvocationMetric(Instant.now(), request.getAction());

src/main/java/software/amazon/cloudformation/proxy/HandlerRequest.java

@@ -35,5 +35,6 @@ public class HandlerRequest<ResourceT, CallbackT> {
     private String stackId;
     private CallbackT callbackContext;
     private Boolean snapshotRequested;
+    private Boolean rollback;
     private RequestContext<CallbackT> requestContext;
 }

src/main/java/software/amazon/cloudformation/proxy/RequestData.java

@@ -28,6 +28,7 @@ public class RequestData<ResourceT> {
     private ResourceT resourceProperties;
     private ResourceT previousResourceProperties;
     private Map<String, String> systemTags;
+    private Map<String, String> previousSystemTags;
     private Map<String, String> stackTags;
     private Map<String, String> previousStackTags;
 }

src/main/java/software/amazon/cloudformation/proxy/ResourceHandlerRequest.java

@@ -38,11 +38,13 @@ public class ResourceHandlerRequest<T> {
     private Map<String, String> desiredResourceTags;
     private Map<String, String> previousResourceTags;
     private Map<String, String> systemTags;
+    private Map<String, String> previousSystemTags;
     private String awsAccountId;
     private String awsPartition;
     private String logicalResourceIdentifier;
     private String nextToken;
     private Boolean snapshotRequested;
+    private Boolean rollback;
     private String region;
     private String stackId;
 }