Upload catalog translation causes an error

Start with the upload catalog and invoice translation entry points in the linked documentation, then trace the reported calls through InvoiceResource.java and LocaleUtils.java. Reproduce the upload using the documented flow and confirm that a locale such as fr_FR no longer reaches LocaleUtils with a trailing slash or produces the reported Invalid locale format error.

The upload catalog translation and upload invoice translation code causes the following error:

org.killbill.billing.client.KillBillClientException: Invalid locale format: fr_FR/

The following stack trace is seen in the Kill Bill logs:

Caused by: java.lang.IllegalArgumentException: Invalid locale format: fr_FR/
	at org.killbill.billing.util.LocaleUtils.toLocale(LocaleUtils.java:50)
	at org.killbill.billing.jaxrs.resources.InvoiceResource.getTemplateResource(InvoiceResource.java:925)
	at org.killbill.billing.jaxrs.resources.InvoiceResource.getCatalogTranslation(InvoiceResource.java:782)
	at org.killbill.billing.jaxrs.resources.InvoiceResource_$$_jvstc52_0._d36getCatalogTranslation(InvoiceResource_$$_jvstc52_0.java)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.glassfish.hk2.utilities.reflection.ReflectionHelper.invoke(ReflectionHelper.java:1268)
	at org.jvnet.hk2.internal.MethodInterceptorHandler$MethodInvocationImpl.proceed(MethodInterceptorHandler.java:164)
	at org.killbill.commons.skeleton.metrics.TimedResourceInterceptor.invoke(TimedResourceInterceptor.java:70)
	at org.jvnet.hk2.internal.MethodInterceptorHandler.invoke(MethodInterceptorHandler.java:97)
	at org.killbill.billing.jaxrs.resources.InvoiceResource_$$_jvstc52_0.getCatalogTranslation(InvoiceResource_$$_jvstc52_0.java)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.base/java.lang.reflect.Method.invoke(Method.java:566)
	at org.glassfish.jersey.server.model.internal.ResourceMethodInvocationHandlerFactory.lambda$static$0(ResourceMethodInvocationHandlerFactory.java:52)
	at org.glassfish.jersey.server.model.internal.AbstractJavaResourceMethodDispatcher$1.run(AbstractJavaResourceMethodDispatcher.java:134)
	... 73 common frames omitted