Add java/fuzz_test.go to test sources

Context
- fuzz_test.go is not listed in the soong/java test sources and is not
  running on CI.

Implementation
- Fix fuzz_test.go and add to test sources

Test: m
Change-Id: If2685c646dec4885fc42d7760992309bfa9da382
diff --git a/java/Android.bp b/java/Android.bp
index 0bf7a0b..9d63319 100644
--- a/java/Android.bp
+++ b/java/Android.bp
@@ -91,6 +91,7 @@
         "dexpreopt_config_test.go",
         "droiddoc_test.go",
         "droidstubs_test.go",
+        "fuzz_test.go",
         "genrule_test.go",
         "hiddenapi_singleton_test.go",
         "jacoco_test.go",