Update UserInactivityView to use MobilePopUp component.

clients/flash/air-client/src/Main.mxml

...h/air-client/src/org/bigbluebutton/air/common/PageEnum.as

...luebutton/air/main/commands/UserInactivityTimerCommand.as

...n/air/main/commands/UserInactivityTimerResponseCommand.as

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

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

...igbluebutton/air/main/views/UserInactivityViewMediator.as

...g/bigbluebutton/air/main/views/skins/MobilePopUpSkin.mxml

...-client/src/org/bigbluebutton/air/poll/views/PollPopUp.as