soong_zip: Add tests

Add test that cover basic command line usage of soong_zip.  -D
is not covered yet as the implementation will be replaced with
one that is also more easily testable in the next patch.

Bug: 116751500
Test: zip_test.go
Change-Id: I5a1bcee74ebc9cb3cf332c36f89bc12c0e807ad2
diff --git a/java/java.go b/java/java.go
index 0bd7857..7fd5344 100644
--- a/java/java.go
+++ b/java/java.go
@@ -95,6 +95,9 @@
 	// list of java libraries that will be compiled into the resulting jar
 	Static_libs []string `android:"arch_variant"`
 
+	// list of native libraries that will be provided in or alongside the resulting jar
+	Jni_libs []string `android:"arch_variant"`
+
 	// manifest file to be included in resulting jar
 	Manifest *string