Though it is a technical term it has come into almost common parlance in recent years.
Its origins are far older than Android - stemming from the early 70s Bell Laboratories UNIX operating system.
The root user on a unix machine is the main administrator account; the one that can do absolutely anything.
In modern parlance that has come to mean to 'get below the regular user structure, to take over the machine at root level, in order to perform tasks not permitted to the regular user' & is now used in that context as a verb.
I rooted my phone yesterday
I'm rooting my phone right now
I'm going to root my phone tomorrow
I guess it's going to be a pretty simple conjugation ;-)