Implement integration test for MXJob related to suspend semantics

[tenzen-y]

What this PR does / why we need it:
I implemented integration test for MXJob related to suspend semantics.

follow-up: #1859

Which issue(s) this PR fixes (optional, in Fixes #<issue number>, #<issue number>, ... format, will close the issue(s) when PR gets merged):
Fixes #

Checklist:

• Docs included if any changes are user facing

[coveralls]

Pull Request Test Coverage Report for Build 5621553708

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+3.4%) to 37.065%

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Totals
Change from base Build 5619754531:	3.4%
Covered Lines:	3625
Relevant Lines:	9780

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💛 - Coveralls

[tenzen-y]

/assign @johnugeorge

[terrytangyuan]

Thanks!

/lgtm

[google-oss-prow]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: tenzen-y, terrytangyuan

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