Enable the CheckStyle warning and fix occurences of it.
Note that the check allows leaving out the comma at the end if both
the left and right curly brackets are on the same line [1].
Also re-wrap some declarations for better readability, and remove
redundant "//" comments.
[1] http://checkstyle.sourceforge.net/config_coding.html#ArrayTrailingComma
Change-Id: Ieeb837724ac699aa5a71861c3887bcfda1941939