CLOUDSTACK-1192: fix collectVmDiskStatistics issue when stopping a vm
CLOUDSTACK-1192: fix collectVmDiskStatistics issue when stopping a vm

(Cherry-picked from commit 65c1c986da2cd14b9138a229ad6843ffbf46f3f4)

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