HPCC-11392 Add keyed field indicator for KEYPATCH to generated xml schema

Signed-off-by: Anthony Fishbeck <anthony.fishbeck@lexisnexis.com>

ecl/hqlcpp/hqlckey.cpp

@@ -1678,7 +1678,7 @@ ABoundActivity * HqlCppTranslator::doBuildActivityKeyPatch(BuildCtx & ctx, IHqlE
     //virtual int getSequence() = 0;
     doBuildSequenceFunc(instance->classctx, querySequence(expr), false);
     HqlExprArray xmlnsAttrs;
-    Owned<IWUResult> result = createDatasetResultSchema(querySequence(expr), NULL, original->queryRecord(), xmlnsAttrs, false, true, 0);
+    Owned<IWUResult> result = createDatasetResultSchema(querySequence(expr), NULL, original->queryRecord(), xmlnsAttrs, false, true, numKeyedFields(original));
 
     buildExpiryHelper(instance->createctx, expr->queryAttribute(expireAtom));