Fix Flake TestPollResourceStatus/resource_stabilizes by removing sleep from test.

[tejal29]

Fixes: #2906

Description

Fixes test flake by setting defaultPollingPeriod to 0
User facing changes

Write n/a if not output or log lines changed and no behavior is changed

Before

n/a
After
n/a

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Submitter Checklist

These are the criteria that every PR should meet, please check them off as you
review them:

• Includes unit tests
• Mentions any output changes.
• Adds documentation as needed: user docs, YAML reference, CLI reference.
• Adds integration tests if needed.

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Double check this list of stuff that's easy to miss:

• If you are adding a example to the examples dir, please copy them to integration/examples
• Every new example added in integration/examples dir, should be tested in integration test

Reviewer Notes

• The code flow looks good.
• Unit test added.
• User facing changes look good.

Release Notes

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[codecov]

Codecov Report

Merging #2934 into master will decrease coverage by 0.11%.
The diff coverage is n/a.

Impacted Files	Coverage Δ
pkg/skaffold/runner/deploy.go	66.66% <0%> (-7.02%)	⬇️
pkg/skaffold/deploy/status_check.go	53.77% <0%> (-2.71%)	⬇️
cmd/skaffold/app/cmd/flags.go	100% <0%> (ø)	⬆️
pkg/skaffold/config/options.go	100% <0%> (ø)	⬆️
pkg/skaffold/runner/runner.go	0% <0%> (ø)	⬆️
pkg/skaffold/runner/render.go	0% <0%> (ø)
cmd/skaffold/app/cmd/render.go	42.1% <0%> (ø)
cmd/skaffold/app/cmd/cmd.go	68.25% <0%> (+0.25%)	⬆️