Revert "Revert "add back the postinstall since it's just a warning""
Revert "Revert "add back the postinstall since it's just a warning""

This reverts commit 982251ce10ece75b7d577da38c2a4814a68e6683.

Thinkmill/react-native-schemes-manager,Thinkmill/react-native-schemes-manager