Break up TransactionTest helpers into util directory

Bug: 140128949
Test: build, boot, SurfaceFlinger_test
Change-Id: I10d29ae47cf29979289469832e2fcd1acefbe45f
diff --git a/services/surfaceflinger/tests/Android.bp b/services/surfaceflinger/tests/Android.bp
index 53a3611..159c2a4 100644
--- a/services/surfaceflinger/tests/Android.bp
+++ b/services/surfaceflinger/tests/Android.bp
@@ -50,6 +50,7 @@
     "fakehwc",
     "hwc2",
     "unittests",
+    "utils",
     "vsync",
     "waitforvsync",
 ]