New Update-with-Start API (temporalio#2337)

Author: stephanos

temporal-sdk/src/main/java/io/temporal/client/UpdateOptions.java

@@ -154,6 +154,13 @@ public void validate() {
     }
   }
 
+  void validateWaitForCompleted() {
+    if (waitForStage != null && waitForStage != WorkflowUpdateStage.COMPLETED) {
+      throw new IllegalArgumentException(
+          "waitForStage must be unspecified or " + WorkflowUpdateStage.COMPLETED);
+    }
+  }
+
   public static final class Builder<T> {
     private String updateName;
     private String updateId;