Add ignore_for_file: camel_case_types to generated file

[RTodorov]

Fixes #463

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[RTodorov]

@googlebot I signed it!

[kevmoo]

An aside for @srawlins – wonder if we should pull these ignores into a constant and DRY up this logic a bit...

[srawlins]

I do like having a comment for why each one might be needed.

[kevmoo]

That could go in the constant definition, right?

[srawlins]

Yeah, it could.

I do hope to eliminate all of these and replace with dart-lang/sdk#46957.

[RTodorov]

In the meantime, could we perhaps get this one merged? :)

[srawlins]

Yeah, the support just landed for "all lints", but it will be introduced in Dart 2.15, which is many moons from now.