RCMR_IN030000UK07-related skeleton processing test fix

Author: ORybak5

gp2gp-translator/src/test/java/uk/nhs/adaptors/pss/translator/service/SkeletonProcessingServiceTests.java

@@ -225,7 +225,7 @@ void When_SkeletonAsWholeUk07Message_Expect_InboundMessagePayloadIsNewRCMRMessag
         inboundMessage.setEbXML(readInboundMessageEbXmlFromFile());
 
         when(attachmentHandlerService.getAttachment(any(), any())).thenReturn(skeletonMessage.getBytes(StandardCharsets.UTF_8));
-        when(xmlParseUtilService.getStringFromDocument(any())).thenReturn(readInboundMessagePayloadFromFile());
+        when(xmlParseUtilService.getStringFromDocument(any())).thenReturn(skeletonMessage);
 
         var newInboundMessage =
             skeletonProcessingService.updateInboundMessageWithSkeleton(attachmentLog, inboundMessage, CONVERSATION_ID);