fix: don't base64 decode secret strings

[oreonl]

I was trying to use the new multi-tenancy functionality in the canary release but was getting an error
2022-08-01T22:51:51Z ERROR Reconciler error {"controller": "horizontalrunnerautoscaler-controller", "controllerGroup": "actions.summerwind.dev", "controllerKind": "HorizontalRunnerAutoscaler", "horizontalRunnerAutoscaler": {"name":"xxxxxxx","namespace":"actions-runner-system"}, "namespace": "actions-runner-system", "name": "xxxxxxx", "reconcileID": "2c994235-92be-40f9-bc42-4f0ada10247c", "error": "strconv.ParseInt: parsing \"\\xdbm\\xf8\\xd3\": invalid syntax"}

The controller is trying to base64 decode the secret values even though they are already being returned unencoded.

I built a docker image from this PR and was able to successfully do multi-tenancy.

[mumoshu]

I very much appreciate you for testing and fixing it! Thank you.
A contribution of this kind greatly helps quicken the new release of ARC ❤️