Revert "remove kA1_Config, as it is no longer supported"

This reverts commit 2d72d8b242eac6e9d30228f5b0a407236491c369.

git-svn-id: http://skia.googlecode.com/svn/trunk@12387 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/tests/ImageDecodingTest.cpp b/tests/ImageDecodingTest.cpp
index 6fcef1d..56193f4 100644
--- a/tests/ImageDecodingTest.cpp
+++ b/tests/ImageDecodingTest.cpp
@@ -148,7 +148,7 @@
         // the list is that each one is different, so we can test
         // to make sure the correct config is chosen.
         const SkBitmap::Config configs[] = {
-            SkBitmap::kA8_Config,
+            SkBitmap::kA1_Config,
             SkBitmap::kA8_Config,
             SkBitmap::kIndex8_Config,
             SkBitmap::kRGB_565_Config,