GCS: Bulk uploading

[AkhileshNegi]

GCS: Bulk uploading

[dlobo]

I would say, lets get a standalone script working first that does the following:

0. To begin with assume all credentials and bucket name comes from a config file / env
1. Given a set of ids, urls, and relative location in the bucket, do a bulk upload to GCS. Also move the files to the right location in the bucket
2. Return a set of ids with the GCS url

Once the above is done, we can integrate with the elixir code base and then do:

1. For each org, generate a set of ids, urls and location
2. Call the above with the right config for the org
3. Use the return value to set the gcs_url

[AkhileshNegi]

Closing this for now. As there were two big things we changed

1. We were syncing outbound media to GCS also, so starting a flow with media for 1000 contacts will create 1000 new entries. So we changed the code to sync only inbound media and it is under control now
2. We'll tweak the code to reuse same media id instead of creating new entry everytime, mentioned in this issue