Changed severity of a few checkstyle rules to error

The rules are:
- no whitespace before
- whitespace after
- modifier order

I noticed we had code coming in without spaces after commas in
parameter strings. This is a task for checkstyle, not code review.
I also upped the priority on the JLS modifier order.

Change-Id: I551ba9cd45f3010fab183f4d89360abc376cd878
Merge "Changed severity of a few checkstyle rules to error"