Marking copy constructor as deleted in test

Previously test declared the copy constructor as private without implementation. Marking it as =delete.

Author: sdavtaker

testing-resources/include/aws/external/gtest.h

@@ -11883,7 +11883,7 @@ class ValueArray2 {
 
  private:
  // No implementation - assignment is unsupported.
- void operator=(const ValueArray2& other);
+ void operator=(const ValueArray2&)=delete;
 
  const T1 v1_;
  const T2 v2_;