Global namespace default value can be problematic

The values file in oop platform chart includes default values for the namespace where the chart will be deployed under global.namespace instead of defaulting to the more common practice of using the current release namespace by default.

While Helm supports removing default values by setting the value to null, this doesn't work correctly for older helm versions when the value to be changed is in a subchart (see helm#12879 and helm#30587). This is a problem when using OSM with a chart that uses the OOP platform as a dependency/subchart, since the current version of helm included by default in the installation is affected by the previously mentioned issues, and as such the namespace value cannot be removed.

Removing the default namespace values (simply commenting them out) would fix the above issues and is also more aligned with how helm charts usually work.