Fix handler setters of RcsResourceObject of resource-encapsulation android api.

Fix handler setters of RcsResourceObject of resource-encapsulation android api.

Handler setters should accept null to erase one set earlier.
It is to make apis consistent between c++ and android.

Additionally an issue caused by using old exception class name is fixed.

Change-Id: I273755b6d2ab48a489d1829aa932b2f675332db6
Signed-off-by: coderhyme <jhyo.kim@samsung.com>
Reviewed-on: https://gerrit.iotivity.org/gerrit/2915
Tested-by: jenkins-iotivity <jenkins-iotivity@opendaylight.org>
Reviewed-by: Hun-je Yeon <hunje.yeon@samsung.com>
Reviewed-by: Madan Lanka <lanka.madan@samsung.com>