KEP-2170: Bind repository into the build environment instead of filecopy

[tenzen-y]

What this PR does / why we need it:
I replaced the approach of copying repository files in the container image build env.
We can avoid the copy of files by using --mont=bind option.

Additionally, I resolved https://docs.docker.com/reference/build-checks/from-as-casing/ warning.

Which issue(s) this PR fixes (optional, in Fixes #<issue number>, #<issue number>, ... format, will close the issue(s) when PR gets merged):
Part-of #2206
Follow-up-of: #2221

Checklist:

• Docs included if any changes are user facing

[coveralls]

Pull Request Test Coverage Report for Build 10408130697

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 7 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.06%) to 33.41%

---

Files with Coverage Reduction	New Missed Lines	%
pkg/controller.v1/mpi/mpijob.go	1	91.06%
pkg/controller.v1/mpi/mpijob_controller.go	6	80.48%

Totals
Change from base Build 10408045115:	-0.06%
Covered Lines:	3942
Relevant Lines:	11799

---

💛 - Coveralls

[andreyvelich]

Thanks @tenzen-y !
/lgtm
/approve

[google-oss-prow]

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