NPE in RestfulServerUtils on dehydrated externalized binaries.

[tadgh]

1. Setup externalized binaries
2. Create a Binary resource which becomes externalized.
3. Attempt to perform a GET on that binary, without specifying a content-type.

2023-04-20 13:20:01.113 [fhir_endpoint.fhirEndpointServer-243] ERROR M:fhir_endpoint R:7ALTlIG4SfglfG3W c.u.f.r.s.i.ExceptionHandlingInterceptor - Failure during REST processing: java.lang.NullPointerException: Cannot read the array length because the return value of "org.hl7.fhir.instance.model.api.IBaseBinary.getContent()" is null
java.lang.NullPointerException: Cannot read the array length because the return value of "org.hl7.fhir.instance.model.api.IBaseBinary.getContent()" is null
	at ca.uhn.fhir.rest.server.RestfulServerUtils.streamResponseAsResource(RestfulServerUtils.java:964)
	at ca.uhn.fhir.rest.server.method.BaseResourceReturningMethodBinding.invokeServer(BaseResourceReturningMethodBinding.java:449)
	at ca.uhn.fhir.rest.server.RestfulServer.handleRequest(RestfulServer.java:1171)
	at ca.uhn.fhir.rest.server.RestfulServer.doGet(RestfulServer.java:417)
	at ca.uhn.fhir.rest.server.RestfulServer.service(RestfulServer.java:1870)
	at ca.cdr.endpoint.fhir.web.BaseFhirEndpointServlet.service(BaseFhirEndpointServlet.java:677)
	at javax.servlet.http.HttpServlet.service(HttpServlet.java:590)
	at ca.cdr.api.web.ResponseHeaderFilter.doFilter(ResponseHeaderFilter.java:72) [2 skipped]
	at ca.cdr.api.web.BlockVerbsFilter.doFilter(BlockVerbsFilter.java:51) [2 skipped]
	at ca.cdr.api.web.JettyHealthCheckFilterHttpResponses.doFilter(JettyHealthCheckFilterHttpResponses.java:94) [50 skipped]
	at ca.cdr.endpoint.fhir.web.FhirEndpointElasticApmFilter.doFilter(FhirEndpointElasticApmFilter.java:60) [2 skipped]
	at ca.cdr.endpoint.fhir.web.FhirEndpointErrorTrapFilter.doFilter(FhirEndpointErrorTrapFilter.java:44) [2 skipped]
	at ca.cdr.api.web.ExceptionLoggerFilter.doFilter(ExceptionLoggerFilter.java:47) [2 skipped]
	at ca.cdr.api.web.DefaultResourcesFilter.doFilter(DefaultResourcesFilter.java:56) [2 skipped]
	at ca.cdr.api.security.SaveModuleInRequestFilter.doFilter(SaveModuleInRequestFilter.java:73) [2 skipped]
	at ca.cdr.api.web.IgnoreInvalidAuthorizationHeaderFilter.doFilter(IgnoreInvalidAuthorizationHeaderFilter.java:50) [2 skipped]
	at ca.cdr.api.web.ClearSecurityFilter.doFilter(ClearSecurityFilter.java:22) [2 skipped]
	at ca.cdr.api.web.HttpTroubleshootingLogFilter.doFilter(HttpTroubleshootingLogFilter.java:72) [2 skipped]
	at ca.cdr.tracing.RequestTracingFilter.doFilter(RequestTracingFilter.java:38) [2 skipped]
	at ca.cdr.api.web.BaseJettyServer$1.runJob(BaseJettyServer.java:419) [25 skipped]
	at java.base/java.lang.Thread.run(Thread.java:833) [1 skipped