Remove visibility change on global helper core service override.

[xserna]

PR coming from #126 (comment)

[emodric]

Can you use public: true to mark it specifically as public, instead of relying on the default Symfony behaviour (and to avoid the deprecation message)?

You can also leave a comment why it is needed to be public.

[andrerom]

@emodric Maybe you can use suggest feature for what you had in mind?

[andrerom]

Thanks @xserna 👏