Add layer flag to allow creating an effect layer without color fill

This change allows creating an effect layers without a color fill so
we can avoid an additional sf transactions when creating effect
layers.

Fixes: 157646690
Test: go/wm-smoke
Test: atest SurfaceFlinger_test
Change-Id: I3d8a4f4820d7b8fb05daab697c25cff8def612c1
diff --git a/services/surfaceflinger/tests/Android.bp b/services/surfaceflinger/tests/Android.bp
index 94ebe89..fe2af80 100644
--- a/services/surfaceflinger/tests/Android.bp
+++ b/services/surfaceflinger/tests/Android.bp
@@ -22,6 +22,7 @@
         "Credentials_test.cpp",
         "DereferenceSurfaceControl_test.cpp",
         "DisplayConfigs_test.cpp",
+        "EffectLayer_test.cpp",
         "InvalidHandles_test.cpp",
         "LayerCallback_test.cpp",
         "LayerRenderTypeTransaction_test.cpp",