The word socialist was added to the constitution because of Indira Gandhi, the only dictator to ever hold power in India. So I think you are making my point for me
Are you seriously arguing that India didn't practice socialist policies before that amendment? And continued to do so for decades afterwards? Arguably continues to do so in some respects even today.
Even the link you provided notes the same thing: "Ambedkar's (the original author of the constitution)...objection [to putting "socialist" in the original preamble] was [it was] "purely superfluous" and "unnecessary", as "socialist principles are already embodied in our Constitution" through Fundamental Rights and the Directive Principles of State Policy."
If the largest democracy in history isn't a "notable example" what is?
1. https://en.wikipedia.org/wiki/Constitution_of_India