[8.19](backport #4870) Enable agent container e2e tests (#5280)

* Enable agent container e2e tests (#4870)

* Enable agent container e2e tests

* Add a retry for integration and e2e tests

* Try setting ryuk to priviledged container

(cherry picked from commit f30b83d)

# Conflicts:
#	.buildkite/pipeline.yml

* Fix merge

---------

Co-authored-by: Michel Laterman <[email protected]>
Co-authored-by: michel-laterman <[email protected]>

Author: mergify[bot]

.buildkite/pipeline.yml

@@ -200,15 +200,29 @@ steps:
           provider: "gcp"
         artifact_paths:
           - build/*.xml
+        plugins:
+          - *bk_analytics_token_plugin
+          - *test_collector_plugin
+        retry:
+          automatic:
+            limit: 1
 
       - label: "E2E Test"
         key: "e2e-test"
         command: ".buildkite/scripts/e2e_test.sh"
+        env:
+          TESTCONTAINERS_RYUK_CONTAINER_PRIVILEGED: "true"
         agents:
           provider: "gcp"
         artifact_paths:
           - build/*.xml
           - build/e2e-coverage.out
+        plugins:
+          - *bk_analytics_token_plugin
+          - *test_collector_plugin
+        retry:
+          automatic:
+            limit: 1
 
       - label: ":junit: Junit annotate"
         agents:

testing/e2e/agent_container_test.go

@@ -37,7 +37,6 @@ type AgentContainerSuite struct {
 }
 
 func TestAgentContainerSuite(t *testing.T) {
-	t.Skip("Flakey test suite skipped. See https://github.com/elastic/fleet-server/issues/3909")
 	suite.Run(t, new(AgentContainerSuite))
 }
 
@@ -90,7 +89,7 @@ func (suite *AgentContainerSuite) TearDownTest() {
 // It checks the status API on the fleet-server's external port and that the agent listed in Kibana states "online"
 // Tests that enroll another agent explicitly need fleet-server to be online
 func (suite *AgentContainerSuite) FleetIsHealthy(bCtx context.Context, endpoint string) {
-	ctx, cancel := context.WithTimeout(bCtx, time.Minute)
+	ctx, cancel := context.WithTimeout(bCtx, 4*time.Minute)
 	defer cancel()
 	suite.FleetServerStatusOK(ctx, endpoint)