Wasm Configuration for Ambient Mode - Updates

[adilmp1]

This PR's modification addresses the resolution of an issue identified in Issue #51014 by John. Since the issue is fixed, we can now apply the WasmPlugin directly to the service instead of applying it to the gateway. Previously, despite providing credentials, requests to other services bypassed authentication, prompting the decision against applying the WasmPlugin directly to the service. Relevant tests have been updated to reflect these changes, although they will encounter failures until the new Istio image incorporating John's fixes is deployed.

Adds documentation as per : istio/istio#42337

[craigbox]

/retest-required

[kfaseela]

it is not ready for merge as he has mentioned in the description of the PR - test will pass only when the testing image is available with John's fix. i think it happens weekly once

[kfaseela]

we need to remove the service specific waypoint proxy from the document. With the fix from @howardjohn it is not needed anymore. And then let us wait till the CI has the latest test image to retest this and see if it passes.

[kfaseela]

/retest

[kfaseela]

/retest

[kfaseela]

/cherrypick release-1.22

[istio-testing]

@kfaseela: #15136 failed to apply on top of branch "release-1.22":

Applying: updated docs and test
.git/rebase-apply/patch:19: trailing whitespace.
      group: ""                       
.git/rebase-apply/patch:36: trailing whitespace.
      group: ""                       
warning: 2 lines add whitespace errors.
Using index info to reconstruct a base tree...
M	go.mod
Falling back to patching base and 3-way merge...
Auto-merging go.mod
CONFLICT (content): Merge conflict in go.mod
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
Patch failed at 0001 updated docs and test
When you have resolved this problem, run "git am --continue".
If you prefer to skip this patch, run "git am --skip" instead.
To restore the original branch and stop patching, run "git am --abort".

In response to this:

/cherrypick release-1.22

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[istio-testing]

@kfaseela: new issue created for failed cherrypick: #15166

In response to this:

/cherrypick release-1.22

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.