rename getChildWorkflowExecution to getWorkflowExecution

Author: Liang Mei

src/main/java/com/uber/cadence/internal/sync/WorkflowInternal.java

@@ -167,7 +167,7 @@ public static <T> T newExternalWorkflowStub(
             new ExternalWorkflowInvocationHandler(execution, getWorkflowInterceptor()));
   }
 
-  public static Promise<WorkflowExecution> getChildWorkflowExecution(Object workflowStub) {
+  public static Promise<WorkflowExecution> getWorkflowExecution(Object workflowStub) {
     if (workflowStub instanceof WorkflowStub) {
       return ((WorkflowStub) workflowStub).__getWorkflowExecution();
     }

src/main/java/com/uber/cadence/workflow/Workflow.java

@@ -443,7 +443,7 @@ public static <R> R newExternalWorkflowStub(
    * as child workflow start is asynchronous.
    */
   public static Promise<WorkflowExecution> getWorkflowExecution(Object childWorkflowStub) {
-    return WorkflowInternal.getChildWorkflowExecution(childWorkflowStub);
+    return WorkflowInternal.getWorkflowExecution(childWorkflowStub);
   }
 
   /**