Make Condition and ReplicaStatus optional

[tenzen-y]

What this PR does / why we need it:
I made jobStatus.Condition and jobStatus.replicaStatus optional. We shouldn't make those fields necessary since those fields can be null.

/assign @johnugeorge

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 5541650459

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 15 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.2%) to 32.962%

---

Files with Coverage Reduction	New Missed Lines	%
pkg/controller.v1/mpi/mpijob_controller.go	6	78.98%
pkg/controller.v1/pytorch/pytorchjob_controller.go	9	59.95%

Totals
Change from base Build 5534487622:	-0.2%
Covered Lines:	3194
Relevant Lines:	9690

---

💛 - Coveralls

[coveralls]

Pull Request Test Coverage Report for Build 5541650459

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 15 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.1%) to 32.982%

---

Files with Coverage Reduction	New Missed Lines	%
pkg/controller.v1/mpi/mpijob_controller.go	6	79.17%
pkg/controller.v1/pytorch/pytorchjob_controller.go	9	59.95%

Totals
Change from base Build 5534487622:	-0.1%
Covered Lines:	3196
Relevant Lines:	9690

---

💛 - Coveralls

[johnugeorge]

/lgtm
/approve

[google-oss-prow]

[APPROVALNOTIFIER] This PR is APPROVED

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

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