lexical_casts: use gMock instead of gTest (#3204) (#3205)

Author: mergify[bot]

hardware_interface/CMakeLists.txt

@@ -90,7 +90,7 @@ if(BUILD_TESTING)
   target_link_libraries(test_helpers hardware_interface)
 
   # Test lexical casts methods
-  ament_add_gtest(test_lexical_casts test/test_lexical_casts.cpp)
+  ament_add_gmock(test_lexical_casts test/test_lexical_casts.cpp)
   target_link_libraries(test_lexical_casts hardware_interface)
 
   ament_add_gmock(test_component_interfaces test/test_component_interfaces.cpp)

hardware_interface/test/test_lexical_casts.cpp

@@ -14,7 +14,7 @@
 
 #include <stdexcept>
 
-#include "gtest/gtest.h"
+#include "gmock/gmock.h"
 
 #include "hardware_interface/lexical_casts.hpp"