Template param for what command occ runs

Template param for what command occ runs

The ConfigCommand parameter overrides the server resource metadata to
specify what command os-collect-config runs whenever any configuration
data changes.

The default is already 'os-refresh-config' so this change has no
effect but it allows a future change to specify an
os-refresh-config --timeout argument to fix bug #1595722.

Change-Id: I8dd35b6724d8c00e5495faca84ee8fee77641b82
Partial-Bug: #1595722