[Tizen][Runtime] Replace application Hide() with Minimize()

When XDG_Shell is enabled, the Minimize() function is properly implemented, original Hide() function cannot hide current application. We should call Minimize() to really hide application.

BUG=XWALK-2578
Merge pull request #2443 from yejingfu/oz-wl

[Tizen][Runtime] Replace application Hide() with Minimize()