Update Banner iframe notes in CHANGELOG
Update Banner iframe notes in CHANGELOG

BranchMetrics/Smart-App-Banner-Deep-Linking-Web-SDK,BranchMetrics/Smart-App-Banner-Deep-Linking-Web-SDK,BranchMetrics/Smart-App-Banner-Deep-Linking-Web-SDK,BranchMetrics/Smart-App-Banner-Deep-Linking-Web-SDK