Update linter to allow non-const references to match more recent google style guide (#920)
Update linter to allow non-const references to match more recent google style guide (#920)

Non-const references are now allowed by google style guide
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