Fix coder corruption in prism while handling flatten

[shunping]

addresses #34587

[lostluck]

Looks like the fix didn't fix testFlattenWithDifferentInputAndOutputCoders2 or testFlattenMultipleCoders. No worries it was worth a shot. But importantly, nothing new started failing.

Revert the change to the build.gradle and then this can be merged in.

[github-actions]

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[shunping]

Looks like the fix didn't fix testFlattenWithDifferentInputAndOutputCoders2 or testFlattenMultipleCoders. No worries it was worth a shot. But importantly, nothing new started failing.

Revert the change to the build.gradle and then this can be merged in.

Done. Thanks!

[github-actions]

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