update handle back button on android

[JustinBeBoy]

close #659

This PR resolve back event not work on android

[dreacot]

sometimes, the back event doesn't register unitl i tap the screen, for example going to the app settings page and tapping back, does nothing until i tap the screen and it refreshes

[JustinBeBoy]

sometimes, the back event doesn't register unitl i tap the screen, for example going to the app settings page and tapping back, does nothing until i tap the screen and it refreshes

done