Check web app's view mode when exiting fullscreen

Check web app's view mode when exiting fullscreen

[Issue#]   PLM P161223-02573
[Problem]  Indicator is visible when user exits fullscreen after watching a video in
           Hotstar web app even if viewmodes="fullscreen" is mentioned in config.xml
[Cause]    When exit fullscreen callback is received, indicator is shown even if viewmode
           of webapp is fullscreen
[Solution] Indicator is not shown if viewmode of webapp is fullscreen

[Verification]
        1) Build and install crosswalk-tizen rpm
        2) Launch Hotstar webapp and play any video
        3) Open fullscreen mode and exit fullscreen
        4) Indicator should not be visible

Change-Id: Ic7452d3da8f7e53ef4768b3f8ed619504fbc208e