Change in vdsm[master]: after_disk_prepare: Add new hook point

[Code Review]

From Dan Kenigsberg :

Dan Kenigsberg has posted comments on this change.

Change subject: after_disk_prepare: Add new hook point
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Patch Set 2:

(2 comments)

https://gerrit.ovirt.org/#/c/71641/2//COMMIT_MSG
Commit Message:

Line 24:         "volumeID": "143e2e28-b2bb-42d4-93c6-835368d3d0ae"
Line 25:     }
Line 26: }
Line 27: 
Line 28: The VM uuid is available via the vmId environment variable.
also vm-level custom properties should be.
Line 29: 
Line 30: The hook is supported only when preparing images before starting a vm.
Line 31: Other flows preparing drives are not supported.
Line 32:

Line 26: }
Line 27: 
Line 28: The VM uuid is available via the vmId environment variable.
Line 29: 
Line 30: The hook is supported only when preparing images before starting a vm.
preparation before hot-plug of a VM should be supported as well.
Line 31: Other flows preparing drives are not supported.
Line 32: 
Line 33: Change-Id: Ib150682c4afd7f387eabf6873b10eb5eaa858417