straight talk and several others from the same international company
have custom 'ROM'/ Operating system
its NOT google issue Android
straight talk and its sister companies do not allow tethering on phones and plans that do not have that feature
i doubt a factory reset will work
you can download an APK file of some hotspot App
and install from an SD card
but then straight talk will very possibly cancel your account
it is in the 'terms of service' of the use of straight talk phone
check one of the low cost data options like visibl or ting
ting.com has a hotspot for $25 a month 30GB 4G LTE, on the Sprint network