Something like account-location but with phone substituted for account within the box.
Mockup:

Or, replace the box with a circle to more closely match Google's Find My Device icon:

Or, if somebody were able to pull the icon used by Google Play Services when Find My Device locates said device:

Made by me,NOT extracted from G Play Services.



I think we should stick to square TBH. It's best we keep to a standard and a circular icon restricts the available space for the inner icon.
Here's the SVG Google use as a map pin:
https://ssl.gstatic.com/android/fmd/static/be8632f979265f2940ae4c912e56d9ac/images/avatar-phone.svg
Most helpful comment
I think we should stick to square TBH. It's best we keep to a standard and a circular icon restricts the available space for the inner icon.