[nova] Set 0 values as strings for HV defaults
[nova] Set 0 values as strings for HV defaults

When setting 0 as 0 instead of as "0", the "merge" function ignores the
values of higher precedence - maybe because it's evaluating to False?
To circumvent this shortcoming, we use "0".

sapcc/helm-charts,sapcc/helm-charts,sapcc/helm-charts,sapcc/helm-charts