Add dexpreopt_bootjars_test.go

Add a test that exercises the dexpreopt_bootjars.go singleton.

Test: dexpreopt_bootjars_test.go
Change-Id: I01d4f6e22f6ff7b809af043391d7b6209dcb8675
diff --git a/Android.bp b/Android.bp
index 4d73049..0f9c2ef 100644
--- a/Android.bp
+++ b/Android.bp
@@ -276,6 +276,7 @@
     testSrcs: [
         "java/app_test.go",
         "java/dexpreopt_test.go",
+        "java/dexpreopt_bootjars_test.go",
         "java/java_test.go",
         "java/jdeps_test.go",
         "java/kotlin_test.go",