Install script broken on `aarch64`

[Wireless4024]

$ uname -m
aarch64

Install script treat aarch64 (arm) as amd64

#find ARCH
if uname -m | grep 64 > /dev/null; then
        ARCH="amd64"
elif uname -m | grep arm > /dev/null; then
        ARCH="arm"
elif uname -m | grep 386 > /dev/null; then
        ARCH="386"
else
        fail "unknown arch: $(uname -m)"
fi

code from (https://kots.io/install)