layout: Do perform a view update transform when unmapped

layout: Do perform a view update transform when unmapped

We should always perform a view update transformed when the view is not
mapped -- or better said when mapping the view. Found while
investigating some certain bevahiours related to surfaces not being
activated by default.

While a dirty+surface damage is sufficient when adding views to layers,
on mapping we should also perform an transform update of the view.

Bug-AGL: SPEC-4302
Signed-off-by: Marius Vlad <marius.vlad@collabora.com>
Change-Id: Ia8e8ed2c4cc165e7fd371a474d85b5fe38bd87fa