Expand visiblity error

Expands the error to suggest a potential fix, giving the package path
for the module that needs visiblity.

Test: go test soong tests
Bug: 168926331
Change-Id: Ie95dec03f5e2c3190bfaed1f0e5789eeb0ab1878
diff --git a/android/visibility_test.go b/android/visibility_test.go
index 9d9e574..cb5ef35 100644
--- a/android/visibility_test.go
+++ b/android/visibility_test.go
@@ -731,7 +731,7 @@
 				}`),
 		},
 		expectedErrors: []string{
-			`module "libnamespace" variant "android_common": depends on //top:libexample which is not visible to this module`,
+			`module "libnamespace" variant "android_common": depends on //top:libexample which is not visible to this module\nYou may need to add "//namespace" to its visibility`,
 		},
 	},
 	{
@@ -760,7 +760,7 @@
 				}`),
 		},
 		expectedErrors: []string{
-			`module "libnamespace" variant "android_common": depends on //top:libexample which is not visible to this module`,
+			`module "libnamespace" variant "android_common": depends on //top:libexample which is not visible to this module\nYou may need to add "//namespace" to its visibility`,
 		},
 	},
 	{