Helm Charts Clean-Up

[Pothulapati]

As the plan is to use helm charts as the core-parts for Linkerd Add-Ons per #3794. It was also planned to make changes to follow best-practices as a pre-requisite.

The following tasks have been taken up for the same:

• Make linkerd2 chart use smaller-case values, support the same for cli and inject`
• Make linkerd2-cni use smaller-case
• Move common values out to global (in preparation for Linkerd Add-Ons #3794 )

@ihcsim @grampelberg

[christyjacob4]

I think this can be closed in light of the merged PRs

[Pothulapati]

Yes, Thanks!