OpTestOpenBMC: Disable one_time boot option
OpTestOpenBMC: Disable one_time boot option

Per https://github.com/openbmc/phosphor-host-ipmid/issues/116

Need to disable the one_time boot object.

There are two boot settings objects - one represents permanent settings,
the other (boot/one_time) applies only to the next boot. If the 'Enabled'
property on the boot/one_time object is set (the default), ipmid reads
this object. If the property is not set, then the /boot object is read.

We first got OpenBMC REST API support in op-test way back in June 2017
with 64312b69acff30de8d75d80ab208c759a522a8ee, and then a few months
later OpenBMC got the one_time support with
13791bd5519d2fe63a4b71f48db32e03c159369a and then
57e8eb7a2d2317b6720e6253800b9be838813140 to fix some initail bugs.

We never changed what we did in op-test with this OpenBMC REST API
change, but managed to avoid having problems mostly through a
combination of expect scripts and dumb luck.

Signed-off-by: Deb McLemore <1938e6bc52a6fb400ff401d42bc5360c2c7aaa30@linux.ibm.com>
[stewart: expand explanation]
Signed-off-by: Stewart Smith <ec31ab75ddf977353c8f660f92ea8b23f64aef25@linux.ibm.com>

open-power/op-test-framework,open-power/op-test-framework,open-power/op-test-framework