Replace default_value_for on ProjectFeature

Ref: #378997 (closed)

What does this MR do and why?

It replaces the usage of default_values_for on ProjectFeature model with a native Rails feature because that gem is unmaintained and it's blocking us from upgrading to Rails 7.

Used a similar technique implemented in !103787 (merged) to deal with existing records and making sure we set correctly their default value.

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