Don't dexpreopt or strip java_test modules

I6bb2c971cee65d2338839753aa0d84939f335b1b accidentally caused
java_test modules to be dexpreopted and possibly stripped.

Test: dexpreopt_test.go
Change-Id: Ida8f046c509c97e38bd3bce66944d32f01530db4
diff --git a/java/dexpreopt_test.go b/java/dexpreopt_test.go
index 5b55799..e4c80dd 100644
--- a/java/dexpreopt_test.go
+++ b/java/dexpreopt_test.go
@@ -83,6 +83,15 @@
 			enabled: false,
 		},
 		{
+			name: "java test",
+			bp: `
+				java_test {
+					name: "foo",
+					srcs: ["a.java"],
+				}`,
+			enabled: false,
+		},
+		{
 			name: "android test",
 			bp: `
 				android_test {