Improve missing apex_available message

The apex available check can traverse quite a long path (5+ steps) to
get from the apex to a module that is missing the apex from its
apex_available property. Understanding where that dependency came from
can often require examining the dependency path which can be difficult.
This change adds the path to the error to simplify that process.

Bug: 153306490
Test: m nothing
Bug: 152762638
Merged-In: Ic4eb169dc2026cd8339d49e23b25d6d1c3879750
Change-Id: Ic4eb169dc2026cd8339d49e23b25d6d1c3879750
diff --git a/apex/apex_test.go b/apex/apex_test.go
index 53c2004..e24a443 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -3515,7 +3515,13 @@
 
 func TestApexAvailable_IndirectDep(t *testing.T) {
 	// libbbaz is an indirect dep
-	testApexError(t, "requires \"libbaz\" that is not available for the APEX", `
+	testApexError(t, `requires "libbaz" that is not available for the APEX. Dependency path:
+.*-> libfoo.*link:shared.*
+.*-> libfoo.*link:static.*
+.*-> libbar.*link:shared.*
+.*-> libbar.*link:static.*
+.*-> libbaz.*link:shared.*
+.*-> libbaz.*link:static.*`, `
 	apex {
 		name: "myapex",
 		key: "myapex.key",