Symfony version(s) affected: 4.2

Description
It's impossible to connect to AWS Elasticache using https://github.com/nrk/predis that supports rediss schema: http://www.iana.org/assignments/uri-schemes/prov/rediss
As a result you get an exception "Unsupported DSN: rediss://{aws-elasticache-uri}"

How to reproduce
You need to set up cache in framework.yml like this:

cache:
        app: cache.adapter.redis
        default_redis_provider: 'rediss://{aws-elasticache-uri}'

As client you need to set up Predis\Client

On init app will throw InvalidArgumentException.

Possible Solution
Add rediss dsn support here: https://github.com/symfony/symfony/blob/master/src/Symfony/Component/Cache/Adapter/AbstractAdapter.php#L135

And here: https://github.com/symfony/symfony/blob/master/src/Symfony/Component/Cache/Traits/RedisTrait.php#L83