[Motion] Split-shade LS transition: fade media when it is not visible on LS

Currently it is trying to perform a guided transition transformation,
but since media is not visible on lock screen, it does not work and
media is being translated from the bottom of the screen.

To fix it, we will change the transformation to be a fade.

Fixes: 223801943
Test: Manually + Unit tests
Change-Id: I1cb46afb9dc7d61b596395dd824f6b9c43152774