metrics: Fix NodeSelector with boolean values

[zeeke]

When using a node selector with boolean values, e.g.:

apiVersion: sriovnetwork.openshift.io/v1
kind: SriovOperatorConfig
metadata:
  name: default
spec:
  configDaemonNodeSelector:
    feature.node.kubernetes.io/network-sriov.capable: "true"

the value needs to be quoted before forwarding it to the metrics-exporter node selector field.

Fixes #766

[github-actions]

Thanks for your PR,
To run vendors CIs, Maintainers can use one of:

• /test-all: To run all tests for all vendors.
• /test-e2e-all: To run all E2E tests for all vendors.
• /test-e2e-nvidia-all: To run all E2E tests for NVIDIA vendor.

To skip the vendors CIs, Maintainers can use one of:

• /skip-all: To skip all tests for all vendors.
• /skip-e2e-all: To skip all E2E tests for all vendors.
• /skip-e2e-nvidia-all: To skip all E2E tests for NVIDIA vendor.
  Best regards.

[coveralls]

Pull Request Test Coverage Report for Build 10613343058

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• 6 unchanged lines in 2 files lost coverage.
• Overall coverage decreased (-0.04%) to 44.981%

---

Files with Coverage Reduction	New Missed Lines	%
controllers/drain_controller.go	1	68.06%
controllers/generic_network_controller.go	5	74.53%

Totals
Change from base Build 10594418576:	-0.04%
Covered Lines:	6600
Relevant Lines:	14673

---

💛 - Coveralls

[SchSeba]

nice catch!

LGTM

[Eoghan1232]

nice! lgtm :)

[zeeke]

got approval from different sides. Merging