Added comment to the OCRepresentation fix

Added comment to the OCRepresentation fix

A build issue is seemingly causing a crash for the Android API
implementation, so the constructors/destructors were all placed
in the .h file.  This commit adds a comment explaining that to the
OCRepresentation code.

Change-Id: I22d0e2a374ea82165d0d7914ebfd2748b5f59c60
Signed-off-by: Erich Keane <erich.keane@intel.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/318
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Patrick Lankswert <patrick.lankswert@intel.com>