Remove Istio dependency from Eventing (Part - 5) - final cleanup

[akashrv]

Fixes: #294
Previous PRs for reference:
#1044
#1058
#1074
#1107

Proposed Changes

• Remove Istio sidecar from all dispatchers
• Remove Istio sidecar from tests

Release Note

All Knative eventing dispatchers, broker ingress and broker filter service will not have side-cars.
Knative Eventing wouldn't need Istio mesh to function, however it will continue work if the mesh is present.

[akashrv]

/assign @Harwayne @vaikas-google

[akashrv]

/retest

[Harwayne]

Will everything work correctly if Istio sidecar injection is enabled? For example, the controller used to opt-out of injection, what happens if the sidecar is present? As might happen if you are running an existing release of Knative eventing, which labels the knative-eventing namespace to forcibly inject the sidecar.

[akashrv]

/retest

[Harwayne]

/lgtm
/approve
/hold

Holding until you have verified that this works both via direct installation from scratch and via upgrade from 0.5. Once you have verified that, feel free to cancel the hold yourself.

[knative-prow-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: akashrv, Harwayne

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• OWNERS [Harwayne]

Approvers can indicate their approval by writing /approve in a comment
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[akashrv]

/lgtm
/approve
/hold

Holding until you have verified that this works both via direct installation from scratch and via upgrade from 0.5. Once you have verified that, feel free to cancel the hold yourself.

Have tested following scenarios:

1. New gke cluster, install 0.5 (istio, serving, eventing), test each channel, upgrade and test all channels again
2. New gke cluster, install 0.6 eventing only, test each channel
   basic test - send one single event to each channel and then to default broker and verify that the subscriber received it.

[knative-metrics-robot]

The following is the coverage report on pkg/.
Say /test pull-knative-eventing-go-coverage to re-run this coverage report

File	Old Coverage	New Coverage	Delta
pkg/provisioners/channel_util.go	92.4%	80.0%	-12.4
pkg/reconciler/containersource/containersource.go	Do not exist	80.2%
pkg/reconciler/containersource/resources/deployment.go	Do not exist	100.0%
pkg/reconciler/cronjobsource/resources/receive_adapter.go	Do not exist	100.0%
pkg/reconciler/v1alpha1/broker/broker.go	89.8%	88.1%	-1.7

[akashrv]

/retest

[Harwayne]

/lgtm
/hold cancel

[akashrv]

/retest