Fix BitmapTest.testExtractAlpha with correct assert statement

The new Bitmap generated by Bitmap.extractAlpha uses the alpha value of
origin Bitmap as color value, so we should use total color value to
compare with origin alpha value.

Signed-off-by: utzcoz <utzcoz@outlook.com>
diff --git a/integration_tests/ctesque/src/test/java/android/graphics/BitmapTest.java b/integration_tests/ctesque/src/test/java/android/graphics/BitmapTest.java
index 86c9fa1..0aa0edd 100644
--- a/integration_tests/ctesque/src/test/java/android/graphics/BitmapTest.java
+++ b/integration_tests/ctesque/src/test/java/android/graphics/BitmapTest.java
@@ -70,7 +70,7 @@
     Bitmap ret = bitmap.extractAlpha();
     int source = bitmap.getPixel(10, 20);
     int result = ret.getPixel(10, 20);
-    assertThat(Color.alpha(result)).isEqualTo(Color.alpha(source));
+    assertThat(result).isEqualTo(Color.alpha(source));
   }
 
   @Test