Revert "Bug 1061466 - Add a basic marionette test for update splash-screen. r=alive" for gaia unit test failure

This reverts commit b4787087c0fe2c906361acd201b31674c00e04a1.
Revert "Bug 1061466 - Show a splash screen when doing a system update. r=alive" for gaia unit test failures

This reverts commit 8088d3e61251ed6d0a1a4f1153a7967cfc9ddef5.