fix(update_chroot): Move to new toolchain_util.sh library
fix(update_chroot): Move to new toolchain_util.sh library

Switch from cros_setup_toolchains to the new simpler toolchain_util code
for installing toolchains in the SDK chroot.

zhang0137/scripts,mjg59/scripts,vmware/coreos-scripts,nicescale/scripts,sigma/coreos-scripts,andrejro/coreos--scripts,nicescale/scripts,bcwaldon/coreos-scripts,crawford/scripts,andrejro/coreos--scripts,vmware/coreos-scripts,endocode/scripts,trnubo/scripts,mjg59/scripts,bcwaldon/coreos-scripts,vmware/coreos-scripts,mischief/scripts,gtank/scripts,bcwaldon/coreos-scripts,zhang0137/scripts,mischief/scripts,fivethreeo/scripts,marineam/coreos-scripts,fivethreeo/scripts,zhang0137/scripts,endocode/scripts,fivethreeo/scripts,smilart/scripts,trnubo/scripts,glevand/coreos--scripts,coreos/scripts,nicescale/scripts,BugRoger/scripts,BugRoger/scripts,gtank/scripts,crawford/scripts,coreos/scripts,gtank/scripts,sigma/coreos-scripts,andrejro/coreos--scripts,smilart/scripts,endocode/scripts,crawford/scripts,mjg59/scripts,marineam/coreos-scripts,marineam/coreos-scripts,mischief/scripts,glevand/coreos--scripts,smilart/scripts,trnubo/scripts,BugRoger/scripts,sigma/coreos-scripts