Use new MobileAlert instead of Spark Alert.

clients/flash/air-client/src/css/hdpi.css

clients/flash/air-client/src/css/ldpi.css

clients/flash/air-client/src/css/mdpi.css

clients/flash/air-client/src/css/xhdpi.css

clients/flash/air-client/src/css/xxhdpi.css

clients/flash/air-client/src/css/xxxhdpi.css

...c/org/bigbluebutton/air/main/views/MenuButtonsMediator.as

...lient/src/org/bigbluebutton/air/main/views/MobileAlert.as

...lient/src/org/bigbluebutton/air/main/views/MobilePopUp.as

...rc/org/bigbluebutton/air/main/views/UserInactivityView.as