[FIX] [BACKPORT] [4.13] Rethrow takeVMSnapshot() exception

[onitake]

Description

Backport of #3546 to 4.13: Rethrow takeVMSnapshot() exception instead of returning null in VMSnapshotManagerImpl.

Contributes to: #3518

Types of changes

• Breaking change (fix or feature that would cause existing functionality to change)
• New feature (non-breaking change which adds functionality)
• Bug fix (non-breaking change which fixes an issue)
• Enhancement (improves an existing feature and functionality)
• Cleanup (Code refactoring and cleanup, that may add test cases)

Screenshots (if appropriate):

How Has This Been Tested?

The change has been tested on the master branch for 4.14. See #3546.

[GabrielBrascher]

Code LGTM

[DaanHoogland]

code is familiar and looks ok, but how did we test this in master?

[DaanHoogland]

@blueorangutan package

[blueorangutan]

@DaanHoogland a Jenkins job has been kicked to build packages. I'll keep you posted as I make progress.

[blueorangutan]

Packaging result: ✖centos6 ✔centos7 ✔debian. JID-640

[onitake]

Are the build errors errors relevant?
I see things like

CloudstackAPIException: Execute cmd: listprojectaccounts failed, due to: errorCode: 431, errorText:Unable to find the project id=9

which doesn't look related to me at all...

[DaanHoogland]

@onitake where do you see those errors?

[DaanHoogland]

@blueorangutan test

[blueorangutan]

@DaanHoogland a Trillian-Jenkins test job (centos7 mgmt + kvm-centos7) has been kicked to run smoke tests

[onitake]

@DaanHoogland They were in the Travis build logs linked here, which was still in "failed" state yesterday. Looks like they were from a different branch or older build?
Or maybe it was simply an intermittent failure.

[blueorangutan]

Trillian test result (tid-809)
Environment: kvm-centos7 (x2), Advanced Networking with Mgmt server 7
Total time taken: 29643 seconds
Marvin logs: https://github.com/blueorangutan/acs-prs/releases/download/trillian/pr3761-t809-kvm-centos7.zip
Smoke tests completed. 77 look OK, 0 have error(s)
Only failed tests results shown below:

Test	Result	Time (s)	Test File

[DaanHoogland]

@DaanHoogland They were in the Travis build logs linked here, which was still in "failed" state yesterday. Looks like they were from a different branch or older build?
Or maybe it was simply an intermittent failure.

maybe, i did re-kick travis, so... Not nice to not be able to rely on CI fully, but this is the complex eco system for you.

[yadvr]

LGTM, this is just a backported change.