mgmt, java, datafactory, fix swagger (Azure#14811)

Author: weidongxu-microsoft

specification/datafactory/resource-manager/readme.java.md

@@ -10,6 +10,14 @@ namespace: com.microsoft.azure.management.datafactory
 license-header: MICROSOFT_MIT_NO_CODEGEN
 payload-flattening-threshold: 1
 output-folder: $(azure-libraries-for-java-folder)/azure-mgmt-datafactory
+
+directive:
+  - from: swagger-document
+    where: "$.definitions.ManagedPrivateEndpoint"
+    transform: delete $.discriminator
+  - from: swagger-document
+    where: "$.definitions.ManagedVirtualNetwork"
+    transform: delete $.discriminator
 ```
 
 # Validation