Lineage properties support module references.

They should have had `android:"path"` tags attached so that users can
point them to filegroup modules.

Test: app_test.go & app_import_test.go
Bug: 182175153
Change-Id: I5580408488ffe5fc12c869cbfb7a468713dcbc96
diff --git a/java/app.go b/java/app.go
index 0660aa6..e98fe31 100755
--- a/java/app.go
+++ b/java/app.go
@@ -122,8 +122,8 @@
 	// or an android_app_certificate module name in the form ":module".
 	Certificate *string
 
-	// Name of the signing certificate lineage file.
-	Lineage *string
+	// Name of the signing certificate lineage file or filegroup module.
+	Lineage *string `android:"path"`
 
 	// the package name of this app. The package name in the manifest file is used if one was not given.
 	Package_name *string