Let tests override environment

Pass an environment to TestConfig that will be used for
all Config.Getenv calls.

Test: none
Change-Id: I683cd9c9e0db61c9bfd2adb27fca78f558f225c4
diff --git a/cc/test_data_test.go b/cc/test_data_test.go
index 962bde5..434edcd 100644
--- a/cc/test_data_test.go
+++ b/cc/test_data_test.go
@@ -117,7 +117,7 @@
 	}
 	defer os.RemoveAll(buildDir)
 
-	config := android.TestConfig(buildDir)
+	config := android.TestConfig(buildDir, nil)
 
 	for _, test := range testDataTests {
 		t.Run(test.name, func(t *testing.T) {