SecureCacheImpl should not require ADMIN permission

DefaultCacheManager methods don't always require ADMIN permission, and if they require a certain permission they request it explicitly.

SecureCacheImpl.getCacheManager() requiring ADMIN restricts access to methods like EmbeddedCacheManager.getAddress() unnecessarily, and forces us to do things like cache the cache manager reference in a field or use a separate security action just to get the cache manager.