[JAVA] Handle camlCase with $ as first char

[Zomzog]

Fix #13291

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[wing328]

Since it's a breaking change with fallback, we'll target 6.2.0 release.

[Zomzog]

Reference

It's not a breaking change with the current version. It can be activated by the flag that is disabled by default.

[wing328]

FYI.

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