Add t.Parallel() to java tests

Speeds up go test ./java from 32 seconds to 9 seconds.

Test: go test ./java
Change-Id: I4c6640e787c0744c6dfda03b7382839b452e24cf
diff --git a/java/container_test.go b/java/container_test.go
index 25cfa4c..515236d 100644
--- a/java/container_test.go
+++ b/java/container_test.go
@@ -26,6 +26,7 @@
 }
 
 func TestJavaContainersModuleProperties(t *testing.T) {
+	t.Parallel()
 	result := android.GroupFixturePreparers(
 		prepareForJavaTest,
 	).RunTestWithBp(t, `