Increase flaky wait_until timeouts in macOS system tests (#51832)

test_stopping_empty_path and test_metricset_process intermittently
timed out on macOS CI runners when the host was under load: filebeat
missed a 5s window to flush its first log line, and process
enumeration missed a 20s window by ~90ms. Both are wait_until()
timeouts, not logic bugs.

(cherry picked from commit c149371)

Author: macdewee

filebeat/tests/system/test_shutdown.py

@@ -191,6 +191,6 @@ def test_stopping_empty_path(self):
         msg = "No paths were defined for input"
         self.wait_until(
             lambda: self.log_contains_count(msg) >= 1,
-            max_timeout=5)
+            max_timeout=15)
 
         filebeat.check_wait(exit_code=1)

x-pack/auditbeat/tests/system/auditbeat_xpack.py

@@ -26,7 +26,7 @@ def setUp(self):
         )
 
     # Adapted from metricbeat.py
-    def check_metricset(self, module, metricset, fields=[], extras={}, errors_allowed=False, warnings_allowed=False):
+    def check_metricset(self, module, metricset, fields=[], extras={}, errors_allowed=False, warnings_allowed=False, max_timeout=20):
         """
         Method to test a metricset for its fields
         """
@@ -39,7 +39,7 @@ def check_metricset(self, module, metricset, fields=[], extras={}, errors_allowe
             "extras": extras,
         }])
         proc = self.start_beat()
-        self.wait_until(lambda: self.output_lines() > 0)
+        self.wait_until(lambda: self.output_lines() > 0, max_timeout=max_timeout)
         proc.check_kill_and_wait()
 
         if not warnings_allowed:

x-pack/auditbeat/tests/system/test_metricsets.py

@@ -76,7 +76,7 @@ def test_metricset_process(self):
         # errors_allowed|warnings_allowed=True - Disabling hashing causes the dataset to add an error to the event
         # and log a warning. That should not fail the test.
         self.check_metricset("system", "process", COMMON_FIELDS + fields, {"process.hash.max_file_size": 1},
-                             errors_allowed=True, warnings_allowed=True)
+                             errors_allowed=True, warnings_allowed=True, max_timeout=40)
 
     @unittest.skipUnless(sys.platform.startswith('linux'), "Only implemented for Linux")
     def test_metricset_user(self):