Fix vcpkg triplet suffix matrix parameter.
Fix vcpkg triplet suffix matrix parameter.

vcpkg_triplet -> vcpkg_triplet_suffix

Also add comments to include/exclude statements to easier understand their effects on the matrix.

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