Refactored SystemServerInitThreadPool.get().submit() into just submit().

Bug: 141571552

Test: manual verification

Change-Id: I1c54e9b66c765956369de2d93063bc4760b79772
diff --git a/services/core/java/com/android/server/biometrics/face/FaceService.java b/services/core/java/com/android/server/biometrics/face/FaceService.java
index 9eb0d50..1b13212 100644
--- a/services/core/java/com/android/server/biometrics/face/FaceService.java
+++ b/services/core/java/com/android/server/biometrics/face/FaceService.java
@@ -1089,7 +1089,7 @@
         publishBinderService(Context.FACE_SERVICE, new FaceServiceWrapper());
         // Get the face daemon on FaceService's on thread so SystemServerInitThreadPool isn't
         // blocked
-        SystemServerInitThreadPool.get().submit(() -> mHandler.post(this::getFaceDaemon),
+        SystemServerInitThreadPool.submit(() -> mHandler.post(this::getFaceDaemon),
                 TAG + ".onStart");
     }