Use correct install paths in generated Android.mk

Extract Soong's install path and put it in the generated Android.mk file
so that tests get installed in the correct place.

Change-Id: Id4726855c5677855406de20773a5da533bdd4cea
diff --git a/cc/cc.go b/cc/cc.go
index d20a197..251d1cd 100644
--- a/cc/cc.go
+++ b/cc/cc.go
@@ -1195,7 +1195,7 @@
 	dir64 string
 	data  bool
 
-	path common.Path
+	path common.OutputPath
 }
 
 var _ installer = (*baseInstaller)(nil)