ArrayIndexOutOfBoundsException during startup

[lmsurpre]

Describe the bug
Following the new steps at https://github.com/IBM/FHIR/wiki/Setting-up-for-development#running-with-the-liberty-maven-plugin we see the following errors during startup:

[INFO] [INFO    ] SRVE9103I: A configuration file for a web server plugin was automatically generated for this server at /Users/lmsurpre/git/fhir/fhir-server-webapp/target/liberty/wlp/usr/servers/defaultServer/logs/state/plugin-cfg.xml.
[INFO] [INFO    ] FFDC1015I: An FFDC Incident has been created: "java.lang.ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0 io.openliberty.microprofile.openapi20.utils.IndexUtils 109" at ffdc_21.12.07_19.29.24.0.log
[INFO] [INFO    ] FFDC1015I: An FFDC Incident has been created: "java.lang.ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0 io.openliberty.microprofile.openapi20.ApplicationProcessor 203" at ffdc_21.12.07_19.29.24.1.log
[INFO] [INFO    ] FFDC1015I: An FFDC Incident has been created: "java.lang.ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0 io.openliberty.microprofile.openapi20.ApplicationProcessor 273" at ffdc_21.12.07_19.29.25.0.log
[INFO] [ERROR   ] CWWKO1661E: An error occurred when processing application fhir-server-webapp and an OpenAPI document was not produced. The error was: java.lang.ArrayIndexOutOfBoundsException: Index 0 out of bounds for length 0.

Environment
main

To Reproduce
Steps to reproduce the behavior:

1. Follow (https://github.com/IBM/FHIR/wiki/Setting-up-for-development#running-with-the-liberty-maven-plugin

Expected behavior
No errors during startup

Additional context
I think its maybe because we have just the fhir-server webapp and not the fhir-openapi one while running in dev mode.
We should see about either:
A. removing/disabling the openapi.xml configDropin (currently under defaults) while running from the liberty maven plugin; or
B. enabling the fhir-openapi war in the test server when running via the liberty maven plugin ; or
C. establishing some other mechanism for serving our openapi definition from the fhir-server-webapp

[lmsurpre]

Looks like this came from the upgrade to Liberty 21.0.0.11 ... too bad we didn't notice before releasing 4.10.2.
The errors should be benign, but we'll have that cleaned up in our next release.

[lmsurpre]

I havn't seen this issue in quite some time, so I think its adequately addressed.
Now that the issue is fixed in Liberty, we might want to take this setting back out when we upgrade Liberty version... but I don't think it will actually hurt anything to leave it.