[Tizen] xwalk should get the installed apps list from AIL

Xwalk should get the installed apps list from AIL (it is possible
since 1e4f86873d11f685169e6bce886fceced59f20ce).

Before this change xwalk used pkgmng which was wrong as a package
and an app are the different things and using both AIL and pkgmng
storages at the same time could lead to data inconsistency.