Fix broken macStyle flags on Roboto-MediumItalic

This is a fix for bug 15432929 "Seeing italics instead of bold"

The Roboto-MediumItalic font had macStyle of 3 (bold italic), which
caused it to be selected as a best match for a request of just bold.
This patch changes it to 2 (italic), leaving all else unchanged.

Change-Id: Ic28934904e11ca34cfede8429520d2d87aaf84cd