oeqa/runtime/cases: Only disable/enable for current boot
Previously doing a stop/start worked, but using a disable/enable does
not work on a read-only rootfs. Add a --runtime flag to systemctl so
that systemd only modifies the current boot and does not attempt to
write to the filesystem.
This also keeps the test from making a permanent (one could argue
policy) change to the running system being tested. i.e. What if the
image being tested had intentionally disabled the timesyncd service in
preference to using chrony or ntpd? The test shouldn't assume that the
user wants the timesyncd service enabled.
Signed-off-by: Wes Lindauer <wesley.lindauer@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
