combine copy and rename into single task

HAving these as two separate tasks caused copy to always be out-of-date when
rename is run, and rename to be out-of-date when rename is done. Gradle
does not like inplace updates of any files. By combining it, the copy+rename
now appear to produce a new artificat that will be up-to-date if no sources
have changed. This caused lot of downstream jars to get rebuilt since this jar
is always out-of-dat and rebuilt everytime.

Author: chakru-r

metadata-events/mxe-schemas/build.gradle

@@ -19,13 +19,15 @@ generateDataTemplate.dependsOn copyMetadataModels
 mainCopySchemas.dependsOn copyMetadataModels
 pegasus.main.generationModes = [PegasusGenerationMode.PEGASUS, PegasusGenerationMode.AVRO]
 
-task copyOriginalAvsc(type: Copy, dependsOn: generateAvroSchema) {
+task renameNamespace(type: Copy, dependsOn: generateAvroSchema) {
   from("src/mainGeneratedAvroSchema/avro")
   into file("src/renamed/avro")
-}
 
-task renameNamespace(type: Exec, dependsOn: copyOriginalAvsc) {
-  commandLine 'bash', './rename-namespace.sh'
+  doLast {
+    project.exec {
+      commandLine 'bash', './rename-namespace.sh'
+    }
+  }
 }
 
 build.dependsOn renameNamespace