Search both CE/DE storage when clearing caches.

Now that we have two data storage locations, we need to scan them
both when freeing up disk space.  Clean up logic to use new
get_known_users() API.

Bug: 26056125
Change-Id: Ic05c0022d6f5eb438967b69402b1900678f3858b
diff --git a/cmds/installd/utils.h b/cmds/installd/utils.h
index 477baea..60df356 100644
--- a/cmds/installd/utils.h
+++ b/cmds/installd/utils.h
@@ -114,13 +114,11 @@
 
 int copy_dir_files(const char *srcname, const char *dstname, uid_t owner, gid_t group);
 
-int lookup_media_dir(char basepath[PATH_MAX], const char *dir);
-
 int64_t data_disk_free(const std::string& data_path);
 
 cache_t* start_cache_collection();
 
-void add_cache_files(cache_t* cache, const char *basepath, const char *cachedir);
+void add_cache_files(cache_t* cache, const std::string& data_path);
 
 void clear_cache_files(const std::string& data_path, cache_t* cache, int64_t free_size);