Add a conformance test for invalid end group tag.

Java and Python/C++ are both non-conformant, since they allow these invalid payloads.

PiperOrigin-RevId: 694312115

conformance/failure_list_java_lite.txt

diff --git a/conformance/failure_list_java_lite.txt b/conformance/failure_list_java_lite.txt
index 1494114..39a0f21 100644
--- a/conformance/failure_list_java_lite.txt
+++ b/conformance/failure_list_java_lite.txt
@@ -6,3 +6,7 @@
 
 Required.*.ProtobufInput.PrematureEofInDelimitedDataForKnownNonRepeatedValue.MESSAGE                               # Should have failed to parse, but didn't.
 Required.*.ProtobufInput.PrematureEofInDelimitedDataForKnownRepeatedValue.MESSAGE                                  # Should have failed to parse, but didn't.
+Required.*.ProtobufInput.UnmatchedEndGroup                                                                         # Should have failed to parse, but didn't.
+Required.*.ProtobufInput.UnmatchedEndGroupUnknown                                                                  # Should have failed to parse, but didn't.
+Required.*.ProtobufInput.UnmatchedEndGroupWithData                                                                 # Should have failed to parse, but didn't.
+Required.*.ProtobufInput.UnmatchedEndGroupWrongType                                                                # Should have failed to parse, but didn't.