[autotest] Fixes for install on trusty

- Apache default site is now named 000-default, try both
- a2enmod version fails on trusty because it's builtin
- libfreetype6-dev puts ft2build.h in a different place.

BUG=None
TEST=run on trusty vm, run on precise vm, goobuntu trusty, open
localhost to confirm AFE is up

Change-Id: I6ea818c873c4dabbafa6c6e2930d5186dfe25df6
Reviewed-on: https://chromium-review.googlesource.com/229940
Tested-by: Michael Janssen <jamuraa@chromium.org>
Reviewed-by: Dan Shi <dshi@chromium.org>
Commit-Queue: Michael Janssen <jamuraa@chromium.org>
2 files changed