Revert "Manual engine roll with disabled service authentication codes (#30919)" (#30930)

This reverts commit 19d6e7b61390311f0b285662ba5e977bae7b0382.
diff --git a/bin/internal/engine.version b/bin/internal/engine.version
index 67c5895..20cf800 100644
--- a/bin/internal/engine.version
+++ b/bin/internal/engine.version
@@ -1 +1 @@
-ae4df6fd189219fc35b27cd5e014bd8445c4e59d
+72986c39ea3669ef26d4d7d7cd0c44f513fcd117
diff --git a/dev/devicelab/lib/framework/runner.dart b/dev/devicelab/lib/framework/runner.dart
index 68885e2..69cbe36 100644
--- a/dev/devicelab/lib/framework/runner.dart
+++ b/dev/devicelab/lib/framework/runner.dart
@@ -32,7 +32,6 @@
   final Process runner = await startProcess(dartBin, <String>[
     '--enable-vm-service=0', // zero causes the system to choose a free port
     '--no-pause-isolates-on-exit',
-    '--disable-service-auth-codes', // TODO(bkonyi): enable auth codes
     taskExecutable,
   ]);
 
@@ -164,4 +163,4 @@
   } else {
     print('Could not determine JAVA_HOME; not shutting down Gradle.');
   }
-}
+}
\ No newline at end of file