[202012][sonic-swss][sonic-utilities] submodule updates

[StormLiangMS]

Why I did it

For sonic-swss

* b0e902a - (HEAD -> 202012, origin/202012) [flex counter] Flex counter threads consume too much CPU resources #9202 (#2031) (26 hours ago) [StormLiangMS]
* ab31560 - Remove redundant calls to get child scheduler group during initialization (#1965) (4 days ago) [Stephen Sun]
* cb5c511 - Fix issue: accumulative headroom can exceed limit in rare scenario (#2020) (4 days ago) [Stephen Sun]
* 046bfcf - Revert partial build temporary work-around (#2037) (5 days ago) [Prince Sunny]

For sonic-utilities

* 239cb5c - (HEAD -> 202012, origin/202012) [flex counter] Flex counter threads consume too much CPU resources. #9202 (#1925) (26 hours ago) [StormLiangMS]

How I did it

How to verify it

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)

[StormLiangMS]

/azp run

[azure-pipelines]

You have several pipelines (over 10) configured to build pull requests in this repository. Specify which pipelines you would like to run by using /azp run [pipelines] command. You can specify multiple pipelines using a comma separated list.

[StormLiangMS]

/azp run Azure.sonic-buildimage

[azure-pipelines]

Azure Pipelines successfully started running 1 pipeline(s).

[liat-grozovik]

@StormLiangMS is this PR is still relevant? if so, can you please update conflicts and rerun checkers?
there are some useful bugs fixes in this submodule update

[qiluo-msft]

Please solve the conflict.

[qiluo-msft]

Should we close this PR? @StormLiangMS

[StormLiangMS]

The submodules are advanced and which already included all changes in the PR, so close this PR.

[StormLiangMS]

@qiluo-msft Sorry, didn't notice the message, I checked, all commits are already included in current 202012, close this PR.