resource_control: fix resource group related ebnf syntax

[glorv]

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• This PR is translated from: #resource_control: fix resource group related ebnf syntax docs-cn#13957
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• ran-huang

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[ran-huang]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: 6017b06

[ti-chi-bot]

In response to a cherrypick label: new pull request created to branch release-7.0: #13555.