Added file cache support behind flag: experimental_local_file_cache

Fixed flows when using requestor pay bucket
Retaining object properties when edit is done

Clean up go.mod for github.com/jacobsa/gcloud

No need for `replace` as gcloud/pull#20 is merged

Handle name conflicts in directory renaming

Redo GoogleCloudPlatform#597. Required for GoogleCloudPlatform#590.

Update Dockerfile for v0.39.2

Update Dockerfile for golang 1.17.5 and gcsfuse 0.39.0

Update Dockerfile for golang 1.17.5 and gcsfuse 0.39.0

Update docs for v0.38.0

Update the Dockerfile to package gcsfuse

Benchmark gRPC with connection pool setting (do not merge)

Benchmark gRPC for read throughput (do not merge)