Revert "ISS-22778: Updated DateTime parsing (#1796)"

[ygit]

This reverts commit 4e43ea3.

Description

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Additional context

Pre-launch Checklist

• The Documentation is updated accordingly, or this PR doesn't require it.
• The ExampleAppChangelog is updated with related tickets, or this PR doesn't require it.
• I updated/added relevant documentation (doc comments with ///).
• I listed at least one issue that this PR fixes in the description above.
• I read and followed the Flutter Style Guide, including Features we expect every widget to implement.
• I added new tests to check the change I am making, or this PR is test-exempt.
• All existing and new tests are passing.