Do not warn on manually linked modules when autolinking disabled

[grabbou]

Had a chat with @janicduplessis and he correctly pointed out that it's not easy to remove warnings even if you do not use autolinking. We should detect the presence and warn if turned on... or, go lazy and only run this path when the function is present in Pod / Gradle files.

[thymikee]

Warnings are getting removed alongside with rnpm in this PR: #1043

[janicduplessis]

@thymikee This issue is about warning when not using autolinking I think, not the ones about deprecated rnpm config.

[thymikee]

Oh right, forgot we have another warning for that!

[github-actions]

There hasn't been any activity on this issue in the past 3 months, so it has been marked as stale and it will be closed automatically if no further activity occurs in the next 7 days.