E2E tests failed on "Language server validation" step

[dmytro-ndp]

Describe the bug

1. Happy path E2E tests failed on "Java LS initialization" step:
   https://codeready-workspaces-jenkins.rhev-ci-vms.eng.rdu2.redhat.com/job/basic-MultiUser-Che-check-e2e-tests-against-k8s/904/console

        ▼ Ide.waitStatusBarContains "Starting Java Language Server"
Known flakiness has occurred https://github.com/eclipse/che/issues/14944
        ▼ DriverHelper.reloadPage
        ▼ Ide.waitStatusBarContains "Starting Java Language Server"
    1) Java LS initialization

  3 passing (6m)
  1 failing

  1) Language server validation
       Java LS initialization:
     TimeoutError: Waiting for element to be located By(css selector, div[id='theia-statusBar'])
Wait timed out after 180002ms

Screencast: https://codeready-workspaces-jenkins.rhev-ci-vms.eng.rdu2.redhat.com/job/basic-MultiUser-Che-check-e2e-tests-against-k8s/904/artifact/tests/e2e/report/executionScreencast/

2. Devfile E2E tests failed on "LS initialization" and "Suggestion invoking" steps:
   https://codeready-workspaces-jenkins.rhev-ci-vms.eng.rdu2.redhat.com/job/basic-MultiUser-Che-check-e2e-tests-against-k8s/905/console

• Vert.x "LS initialization" screenshot
  

• Vert.x "Suggestion invoking" screenshot
  

Che version

• latest
• nightly
• other: please specify

Steps to reproduce

• Happy path tests script
• Devfile E2E tests scripts

Expected behavior

Runtime

• kubernetes (include output of kubectl version)
• Openshift (include output of oc version)
• minikube (include output of minikube version and kubectl version)
• minishift (include output of minishift version and oc version)
• docker-desktop + K8S (include output of docker version and kubectl version)
• other: (please specify)

Installation method

• chectl:next with operator installer
• che-operator
• minishift-addon
• I don't know

Environment

• my computer
  • Windows
  • Linux
  • macOS
• Cloud
  • Amazon
  • Azure
  • GCE
  • other (please specify)
• other: CRW CCI

[tsmaeder]

For what it's worth, Java support seems to start just fine on nightly.

[dmytro-ndp]

The possible reason of issue are changes in che-plugin-registry.

[Ohrimenko1988]

Done #16031