Move bottomScripts() call in SkinTemplate

Move bottomScripts() call in SkinTemplate

SkinTemplateNavigation::SpecialPage in buildContentNavigationUrls() and
possibly other hooks are susceptible to adding bottom scripts to
the skin's OutputPage.

It's safer to add the bottom scripts to the template
as late as we can, as doing so will instantiate the rlClient and
populate it with the scripts collected at that point.

Bug: T87871
Change-Id: I000365a7542167d8531d6984d3a1ef6c362034ab