Call service methods even in dry-run mode.

Otherwise the promises inside the method are not evaluated at all,
and no insight is provided into whether cf-agent would have modified
the system.

Since the promises then respect DRYRUN mode, nothing will changed
on the system.

If action_policy is set to warn_only, the methods promise will
respect that and not evaluate the bundle.

This follows up on commit 65c15626992d608eaa51ca3d47b6ccf4e8058576.

See Redmine #5924
Merge pull request #1870 from vohi/redmine/5924-2

Call service methods even in dry-run mode.