pull -r remote: Disregards specified http remote

[simonlsk]

Bug Report

Description

When running dvc pull -r <remote>, the requests sent in order to retrieve directory data are sent to the default remote instead of the specified one.

Reproduce

1. git clone repo (that has dvc directories)
2. dvc remote add <remote> <http-remote>
3. dvc pull -r <remote>

Expected

DVC pull should try to fetch the data from the specified remote

Environment information

MacOS

Output of dvc doctor:

DVC version: 2.7.2 (pip)
---------------------------------
Platform: Python 3.7.6 on Darwin-20.6.0-x86_64-i386-64bit
Supports:
	http (aiohttp = 3.7.4.post0, aiohttp-retry = 2.4.5),
	https (aiohttp = 3.7.4.post0, aiohttp-retry = 2.4.5)
Cache types: reflink, hardlink, symlink
Cache directory: apfs on /dev/disk1s2s1
Caches: local
Remotes: https, http
Workspace directory: apfs on /dev/disk1s2s1
Repo: dvc, git

Additional Information (if any):
The bug seems to have been introduced with #6486
In the following code (dvc/output.py):

def get_dir_cache(self, **kwargs):
        if not self.is_dir_checksum:
            raise DvcException("cannot get dir cache for file checksum")

        obj = self.odb.get(self.hash_info)
        try:
            objects.check(self.odb, obj)
        except FileNotFoundError:
            remote = self.repo.cloud.get_remote_odb(self.remote). # <---- here self.remote is None if nothing is specified for the output instead of falling back to kwargs["remote"]
            self.repo.cloud.pull([obj.hash_info], odb=remote, **kwargs)