CLOUDSTACK-3728:  same issue as CLOUDSTACK-3719
CLOUDSTACK-3728:  same issue as CLOUDSTACK-3719

Make the size explicit parameter to random_gen() for snapshot data

Signed-off-by: Prasanna Santhanam <82219615980488abd2acc1a3d71cfb58f0b2b8b6@apache.org>

mufaddalq/cloudstack-datera-driver,mufaddalq/cloudstack-datera-driver,mufaddalq/cloudstack-datera-driver,mufaddalq/cloudstack-datera-driver,mufaddalq/cloudstack-datera-driver,mufaddalq/cloudstack-datera-driver