Validator is sending peer.TxValidationCode_INVALID_OTHER_REASON instead of
peer.TxValidationCode_ENDORSEMENT_POLICY_FAILURE due to a wrong type check.

Added UT to cover the switch and ensure correct tx flag been assigned.

Change-Id: I7abe8828323780d527b24905f54d9a06e5f70b4e
Signed-off-by: Srinivasan Muralidharan <muralisr@us.ibm.com>
Signed-off-by: Artem Barger <bartem@il.ibm.com>