fix(google-maps): fix event listeners
fix(google-maps): fix event listeners

fixes #999

driftyco/ionic-native,xueron/ionic-native,klirix/ionic-native,xueron/ionic-native,driftyco/ionic-native,klirix/ionic-native,klirix/ionic-native,driftyco/ionic-native,xueron/ionic-native,xueron/ionic-native