This is the reason that when I travel I carry two phones. One is the phone I actually use, and the other is the one I give to authorities when they ask for my phone. It is astonishing to me that not once have I ever been asked if I have a second phone. (It will be an interesting experiment to see if that happens now that I have posted this here.)
Where do authorities ask for your phone? Just curious
Do you know the worst part? Once you unlock your phone and give them your passcode, they take it away and tell you to wait. So now have no idea what they are doing with your phone. Would you trust that device? That is why a burner phone is needed, I guess.