Fix backward incompatible method signature change in batch2 JobDefinitionStartRequest (#7131)

* Restore the old method definition of setJobDefinitionId(), and alter the new one with a different method name.  Call the new method from the unit test.

* Remove the return this method and adjust the unit test.

Author: lukedegruchy

hapi-fhir-docs/src/main/resources/ca/uhn/hapi/fhir/changelog/8_4_0/7130-backward-incompatible-batch2-library.yaml

@@ -0,0 +1,6 @@
+---
+type: fix
+issue: 7130
+title: "There is an API backward incompatibility issue with the hapi-fhir-storage-batch-2 library that may break some 
+        client applications.
+        This has been fixed."

hapi-fhir-storage-batch2-test-utilities/src/test/java/ca/uhn/hapi/fhir/batch2/test/inline/InlineJobCoordinatorTest.java

@@ -136,7 +136,8 @@ void testWithStubJobs() {
 
 		// Some sort of batch service would trigger this:
 		final InlineTestJobParams jobParams = new InlineTestJobParams(30);
-		final JobInstanceStartRequest jobInstanceStartRequest = new JobInstanceStartRequest().setParameters(jobParams).setJobDefinitionId(JOB_DEFINITION_ID);
+		final JobInstanceStartRequest jobInstanceStartRequest = new JobInstanceStartRequest().setParameters(jobParams);
+		jobInstanceStartRequest.setJobDefinitionId(JOB_DEFINITION_ID);
 		// This is the contract for the tests to pass their own job instance ID:
 		final SystemRequestDetails requestDetails = new SystemRequestDetails();
 		requestDetails.addHeader(InlineJobCoordinator.JOB_INSTANCE_ID_FOR_TESTING, JOB_INSTANCE_ID);

hapi-fhir-storage-batch2/src/main/java/ca/uhn/fhir/batch2/model/JobInstanceStartRequest.java

@@ -70,9 +70,8 @@ public String getJobDefinitionId() {
 		return myJobDefinitionId;
 	}
 
-	public JobInstanceStartRequest setJobDefinitionId(String theJobDefinitionId) {
+	public void setJobDefinitionId(String theJobDefinitionId) {
 		myJobDefinitionId = theJobDefinitionId;
-		return this;
 	}
 
 	public String getParameters() {