Assign modified string for sdk directory
Assign modified string for sdk directory

Previousy commit tried to replace slashes, but forgot to reassign the modified string back to the variable it was supposed to modify.

firebase/firebase-cpp-sdk,firebase/firebase-cpp-sdk,firebase/firebase-cpp-sdk,firebase/firebase-cpp-sdk,firebase/firebase-cpp-sdk,firebase/firebase-cpp-sdk,firebase/firebase-cpp-sdk,firebase/firebase-cpp-sdk