factory: update owner and group for root

Update the exec root owner and group for factory_post_boot

Bug: 222226268
Test: pidx=`adb shell pidof adbd` && adb shell cat proc/$pidx/task/$pidx/sched | grep "adbd \|effective uclamp.min"
Change-Id: I7ad3fc9f2db8bd4d6f4c3d2fdf1de1abc0ddcb16
1 file changed