[PATCH] Allow the app to filter the back key even at the top level

[Marco Martin]

On Sunday 14 February 2016, Dirk Hohndel wrote:
> The onBackRequested trick didn't work on the top level page. Which seems
> odd to me - why shouldn't an application be allowed to prevent the back
> key from exiting?

thanks, added. REgardless of the reasons should lways be possible to filter.

> Now imagine we want to allow the user to change credentials. Simple,
> right? Just go back to the other incarnation of that top page. But how do
> you change your mind and go back? Easy again. Hit the back button.

yeah, looks weird, could probably be worth to separe the credential page as a 
separate thing, that can then be accessed by the general menu

-- 
Marco Martin