Revert "Bug 849988 - Implement support for a removable property for preinstalled apps to define if the app can be uninstalled or not r=ferjm" as it renders gaia unbootable in normal (non-production) builds.

This reverts commit 718b76a95d2bc8ecf928d56a308b36cd8b69b3bc.
Merge branch 'master' of https://github.com/mozilla-b2g/gaia