Fix CS warnings in cds-access-api and enable enforcement

Fix CS warnings in cds-access-api and enable enforcement

Fixed checkstyle warnings and enabled enforcement. Most of the
warnings/changes were for:
 - variable name too short
 - correct ordering of @Nonnull annotations
 - line too long
 - suppressing CS RedundantModifier warning for ctors where public is needed
   for packaged-scoped classes that implement Externalizable
 - adding protected to ctors for packaged-scoped abstract classes that
   implement Externalizable to avoid CS RedundantModifier warning
 - local vars/params hiding a field
 - putting overloaded methods close to one another

Change-Id: Ib85e15f21118f3484ccb8e945e8257ae3e3278bc
Signed-off-by: Tom Pantelis <tpanteli@brocade.com>