Fix Layout.isRtlCharAt

We weren't getting correct results from Layout.isRtlCharAt, because it
was only testing half of the correct predicate for whether the argument
was inside the run. This patch restores the correct predicate.

Bug: 17381011
Change-Id: Ib0a77cc182f4ca4bfe824e85b7aff7268f465d73
1 file changed