CXX Performer is failing Meta Error Validation tests

The tests in the file MetaErrorValidationTest are failing because the performer isn't throwing a StatusRuntimeException and instead hitting the assertion fail further in the test. 

These two tests are purposefully supposed to throw exceptions to ensure the performer follows the expected behaviour rules.

This is just a performer issue rather than an SDK issue, but it could cause false passes or failures in the future if the performer doesn't behave as expected.