[Feature] Adjust securityContext for MS-managed containers

**Is your feature request related to a problem? Please describe.**

During our work on security improvements, we found that MS Defender is recommending ```Least privileged Linux capabilities should be enforced for containers ``` and ```securityContext. capabilities``` should be set to ```DROP: ["ALL"]```. After further checks, we found that some of the MS-managed containers, such as kube-proxy or azure-cns, don't align with this recommendation.

**Describe the solution you'd like**

We would like to have these containers' securityContext adjusted to follow the security recommendations, with ALL capabilities dropped and only add the needed.

**Describe alternatives you've considered**

MS recommendation could be hidden by exempting the kube-system namespace, but that doesn't mitigate security risks.

**Additional context**

We have been informed by the MS support engineer that elevated privileges are necessary for them to perform essential networking and orchestration tasks, such as managing IP tables or interfacing with the host network. However, we are unsure if all capabilities are being utilised and don't see a clear reason not to adjust them.