[Chainsaw Tests] Add Chainsaw tests for the sample policy disallow-proc-mount

[erisnar]

Related Issue(s)

#956

Description

Adds chainsaw tests to sample policy

Checklist

• I have read the policy contribution guidelines.
• I have added test manifests and resources covering both positive and negative tests that prove this policy works as intended.
• [] I have added the artifacthub-pkg.yml file and have verified it is complete and correct.

[chipzoller]

The tests for this are failing, the reason being, as noted in the description for this policy, Kubernetes will not allow any other procMount value to be set other than Default unless a corresponding feature gate is set. Since the clusters used to perform these tests do not set this feature gate, and not do we want to, writing this test isn't going to be possible (which is why no Chainsaw test was included by default).