Keeps global settings aligned across entities used in the test for St…

…atsEventFactory

Fixes a potential flaky test, due to shared (LogStash:SETTINGS) fixture across the test base.


Forward port the commit 609155a used to fix the non clean backport PR elastic#16531 of elastic#16525 to 8.x.

LogStash:SETTINGS is used in the constructor of LogStash::Inputs::Metrics::StatsEventFactory to query the value of api.enabled. This PR keeps updated the value for the setting provided to the Agent constructor and to the StatsEventFactory.

x-pack/spec/monitoring/inputs/metrics/stats_event_factory_spec.rb

@@ -59,6 +59,8 @@
   let(:agent_task) { start_agent(agent) }
 
   before :each do
+    @existing_api_enabled = LogStash::SETTINGS.get_value("api.enabled")
+    LogStash::SETTINGS.set_value("api.enabled", webserver_enabled)
     agent
     agent_task
 
@@ -86,6 +88,7 @@
   after :each do
     agent.shutdown
     agent_task.wait
+    LogStash::SETTINGS.set_value("api.enabled", @existing_api_enabled)
     LogStash::SETTINGS.set_value("monitoring.enabled", false)
   end