Fix LSS->Markup transition in RTL

We were constraining the transition view to the start, but
adjusting its location using paddingLeft, etc, which led to
incorrect behavior in RTL. Instead constrain to left so that
everything is consistent.

Bug: 190757843
Fix: 190757843
Test: manual
Change-Id: I07becea2ee0e11d74a1aac350aa7d0693d712bfb