Enable Linkerd proxy injection to work without "automountServiceAccountToken" set to true

[HighWatersDev]

Feature Request

Enable Linkerd to inject proxy without needing automountServiceAccountToken set to true for mTLS.

What problem are you trying to solve?

By default automountServiceAccountToken is set to false. This is also recommended setting in certain environments.

How should the problem be solved?

One of the proposed solutions is to use token volume projection ref.

The other possible solution is to use admission controller as implemented by some other mesh services.

What do you want to happen? Add any considered drawbacks.

Alternative method of injecting proxy sidecar for mTLS without using service account token automount option.

Previously discussed in this issue: #4651

[snoord]

I think this is resolved by #7117

[olix0r]

@snoord I think you're correct. It would be good to add a test that checks that a pod with automountServiceAccounToken: false becomes ready