Rename ColorLayer to EffectLayer to handle both shadows and color fill

We want the ability for a layer to render shadows without any content.
This new layer type will be able to combine effects as needed.

Test: presubmit tests (no functional changes)
Test: go/wm-smoke
Change-Id: I8663d126a23263a3d7dc799d39a9cf44b3b6e4a0
diff --git a/services/surfaceflinger/tests/MultiDisplayLayerBounds_test.cpp b/services/surfaceflinger/tests/MultiDisplayLayerBounds_test.cpp
index c9fdc3b..f8a5b40 100644
--- a/services/surfaceflinger/tests/MultiDisplayLayerBounds_test.cpp
+++ b/services/surfaceflinger/tests/MultiDisplayLayerBounds_test.cpp
@@ -66,7 +66,7 @@
     void createColorLayer(uint32_t layerStack) {
         mColorLayer =
                 createSurface(mClient, "ColorLayer", 0 /* buffer width */, 0 /* buffer height */,
-                              PIXEL_FORMAT_RGBA_8888, ISurfaceComposerClient::eFXSurfaceColor);
+                              PIXEL_FORMAT_RGBA_8888, ISurfaceComposerClient::eFXSurfaceEffect);
         ASSERT_TRUE(mColorLayer != nullptr);
         ASSERT_TRUE(mColorLayer->isValid());
         asTransaction([&](Transaction& t) {