Ingesting latest US Core leads to 500 due to collision in ValueSet oids

[lukedegruchy]

Describe the bug
When using hapi-fhir to ingest US Core the import fails with a 500. This is because hapi-fhir can't process colliding ValueSets with the same oids, even though the ValueSet versions and URLs are totally different.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://www.hl7.org/fhir/us/core/downloads.html and download the tarball
2. Put package.tgz in the classpath directory
3. Run hapi-fhir
4. Trigger an ingestion of package.tgz with the below JSON
5. Wait several minutes. It could be as long as half an hour or more
6. Eventually, the ingestion will fail with a 500.

{
  "name" : "hl7.fhir.us.core",
  "version" : "6.1.0",
  "packageUrl" : "classpath:/package.tgz",
  "installMode" : "STORE_AND_INSTALL",
  "reloadExisting" : true,
  "fetchDependencies" : true
}

There are numerous other errors that are non-fatal.

The below error is the fatal error that terminates the ingestion:

Caused by: ca.uhn.fhir.rest.server.exceptions.ResourceVersionConflictException: HAPI-0989: Trying to update ValueSet/2.16.840.1.113762.1.4.1010.9/_history/43 but this is not the current version

Expected behavior
The ingestion should complete with a 200 or some other indicator or success. There may be other non-fatal errors in the logs, especially with post-processing, but they are not the concern of this bug report.

Environment (please complete the following information):

• HAPI FHIR Version: rel_6_8