Update Core CHANGELOG for M26 (#1353)
Update Core CHANGELOG for M26 (#1353)

We also forgot a few changes in here, updating now so it's up to date.
firebase/firebase-ios-sdk,firebase/firebase-ios-sdk,firebase/firebase-ios-sdk,firebase/firebase-ios-sdk,firebase/firebase-ios-sdk,firebase/firebase-ios-sdk,firebase/firebase-ios-sdk