Only turn on CPP stub test flag

Author: Cynthia Jiang

build_bash.sh

@@ -36,7 +36,7 @@ fi
 
 CMAKE_OPTIONS="${CMAKE_OPTIONS} -DUNITY_ROOT_DIR=${UNITY_ROOT_DIR}"
 CMAKE_OPTIONS="${CMAKE_OPTIONS} -DFIREBASE_UNITY_BUILD_TESTS=ON"
-CMAKE_OPTIONS="${CMAKE_OPTIONS} -DFIREBASE_CPP_BUILD_TESTS=ON"
+CMAKE_OPTIONS="${CMAKE_OPTIONS} -DFIREBASE_CPP_BUILD_STUB_TESTS=ON"
 
 # TODO: Fix mono build to not need unity deps
 build_options=(