I’ve been asked to hand over my phone when I entered India as a visitor with a valid visa. Yes it was a burner phone. Yes the officer questioned me after seeing only 7 photos in the entire Photos app. It was very obvious that it was a burner phone. I didn’t deceive the officer, instead I just nicely explained why this was a burner phone.
Yep, travelling outside your country of origin, expect that your phone/laptop/ect is subject to search. Anything on you is, it's literally stated. Want to push against that? Sure, makes sense, but just carry a burner phone/device and not worry about it. Literally what the US government recommends when traveling to places like China.