Update the scalar bar build time.

The BuildTime member is not being updated when the
scalar bar layout is recalculated, causing layouts
to be recomputed every time the bar is rendered.

Change-Id: Ib5f8e69573383d2c7cf04ca9cfb18b70fbc40dcb
Merge topic '14095_scalar_bar_redraws-rel' into master

155b7f30 Update the scalar bar build time.