This will allow objects to be evicted to Google Cloud Storage when Plasma runs out of memory.

Reporter: Clark Zinzow

Related issues:

• [C++] Add filesystem / IO implementation for Google Cloud Storage (is blocked by)
• [Plasma] Add S3 as external store for Plasma (is related to)

_{Note: This issue was originally created as ARROW-8031. Please see the migration documentation for further details.}