Improved experimental highlighter settings

These settings will improve quality of snippets.  The tests will only pass
with the new 0.0.5 release of the highlighter though.

Bug: 64259
Change-Id: If970dea018eb631af13f561e33f11bbf1d2395b2
(cherry picked from commit ab93e0f2984f94d805c51eb04c89b2acd3a6ee1f)