[docker-ptf] Upgrade to buster

[msosyak]

Why I did it

To make docker ptf buster based

How I did it

Update docker file

How to verify it

make init
make configure PLATFORM=vs
make target/docker-ptf.gz

Which release branch to backport (provide reason below if selected)

• 201811
• 201911
• 202006
• 202012
• 202106

Description for the changelog

A picture of a cute animal (not mandatory but encouraged)

[yxieca]

@msosyak did you run sonic-mgmt test suite with a new PTF docker based off buster?

Can you clarify the intention of upgrading ptf to buster base?

[msosyak]

Yes. I have run sanity regression with few tests from t1 and t0 and all passed as expected.

My intention is to align all docker bases to avoid building a stretch slave image.

[msosyak]

@yxieca Do you see any issues with that update or could we merge this PR?

[yxieca]

@msosyak , do you have the capability of running a full nightly test with buster ptf and compare the results with stretch ptf? If the test results are the same, then we can proceed with this upgrade.

[msosyak]

@yxieca Apologies for the late response. I was in PTO. Yes, I have run the regression and the result for the docker-ptf buster is the same as for the docker-ptf stretch.

[msosyak]

Could we marge this or something else is needed?

[msosyak]

@yxieca Please update