Default node policy when attaching policies by ARN

[mirzaprangon]

I am attaching policies by arn.
After reading the documents, it was unclear that the AmazonEKSWorkerNodePolicy, AmazonEKS_CNI_Policy and AmazonEC2ContainerRegistryReadOnly - these three are the only ones that needed to be included.

I checked the documentation commits, apprantly this part of document was last updated about a years ago in #3815. IMO, The documentation is still unclear. I could not say for sure that the three policies written is indeed the only ones that are default policies, and I should include them when adding any policies by ARN.