[material-ui][AccordionSummary] Fix applying styles from theme

[sai6855]

According to the code below, styles applied to gutters and contentGutters should be applied to the root and content slots respectively when disabledGutters is false. Previously, the styles weren't applied correctly, when styles are passed through theme. This PR fixes that issue.

https://github.com/mui/material-ui/blob/64a093af2d76ae0bde17443fb2eb4488392bdaa3/packages/mui-material/src/AccordionSummary/AccordionSummary.js#L18-L20

before: https://codesandbox.io/s/festive-pond-8qwpsl after: https://codesandbox.io/s/inspiring-glitter-xyxrlc?file=/src/Demo.tsx

Not sure about argos issue, don't think it's related to this PR

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