Update Java checkstyle naming convention for static final fields.

Static final fields can either be "true" constants, e.g.
  static final int HEIGHT_PX = 30;
  static final String TAG = "MyClass"

or can have mutable state or not "feel" like a constant, e.g.
  static final AtomicInteger sNextId;
  static final Runnable sSuspendTask;

This allows either naming convention, FIELD_NAME or sFieldName, at the
programmer's discretion.

NOTRY=true

Review URL: https://codereview.chromium.org/112023009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@243316 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 243316