fix: make RudderTyperUtils.java compilable with -werror

[TWiStErRob]

Description 📝

The generated code has problems with Java's built-in compiler checks when used with -Werror:

warning: [rawtypes] found raw type: List
warning: [unchecked] unchecked call to add(E) as a member of the raw type List
error: warnings found and -Werror specified
1 error
4 warnings
warnings found and -Werror specified

Fixing the rawtypes problems fixes the others.

[contributor-support]

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