[VTS] BlendMode::Coverage test

Enable BlendMode::Coverage test.
Test pass: BlendMode/GraphicsBlendModeCompositionTest#Premultiplied/0: PASSED (930ms)
BlendMode/GraphicsBlendModeCompositionTest#Premultiplied/1: PASSED (933ms)

BUG: 219737571

Test: atest VtsHalGraphicsComposer3_TargetTest
Change-Id: I5f5bbf371c26933457eec0f3710d47ddadd06cdb
diff --git a/graphics/composer/aidl/android/hardware/graphics/composer3/vts/functional/VtsHalGraphicsComposer3_ReadbackTest.cpp b/graphics/composer/aidl/android/hardware/graphics/composer3/vts/functional/VtsHalGraphicsComposer3_ReadbackTest.cpp
index 55a8c70..8098961 100644
--- a/graphics/composer/aidl/android/hardware/graphics/composer3/vts/functional/VtsHalGraphicsComposer3_ReadbackTest.cpp
+++ b/graphics/composer/aidl/android/hardware/graphics/composer3/vts/functional/VtsHalGraphicsComposer3_ReadbackTest.cpp
@@ -1181,8 +1181,7 @@
     }
 }
 
-// TODO(b/219737571) Enable test for HWC3.0 after we matched with 2.4
-TEST_P(GraphicsBlendModeCompositionTest, DISABLED_Coverage) {
+TEST_P(GraphicsBlendModeCompositionTest, Coverage) {
     for (ColorMode mode : mTestColorModes) {
         EXPECT_TRUE(mComposerClient
                             ->setColorMode(getPrimaryDisplayId(), mode, RenderIntent::COLORIMETRIC)