Update csi-snapshotter to "v1.2.1"

[pavannd1]

Description

• Need to update csi-snapshotter in the trident-csi deployment to v1.2.1.
• The version v1.2.1 is a cherry pick update with fix for the issue: Snapshotter uses ListSnapshots on drivers which do not advertise it. kubernetes-csi/external-snapshotter#132
• Since Trident doesn't implement ListSnapshots, the current version fails to bind statically provisioned VolumeSnapshot and VolumeSnapshotContent

Logs

Logs from trident-csi/csi-snapshotter:

I0814 18:23:32.848143       1 util.go:138] storeObjectUpdate updating content "csi-snap-static-content" with version 1314595
I0814 18:23:32.848155       1 snapshot_controller.go:274] Check and update snapshot default/csi-snap-static status
I0814 18:23:32.848161       1 snapshot_controller.go:384] checkandUpdateSnapshotStatus[default/csi-snap-static] started
I0814 18:23:32.848167       1 snapshot_controller.go:339] scheduleOperation[check-default/csi-snap-static[9f5ff2c5-bec0-11e9-98a6-026aef9e136c]]
I0814 18:23:32.848192       1 snapshot_controller.go:573] checkandUpdateBoundSnapshotStatusOperation: checking whether snapshot [csi-snap-static] is pre-bound to content [csi-snap-static-content]
I0814 18:23:32.848209       1 connection.go:180] GRPC call: /csi.v1.Controller/ListSnapshots
I0814 18:23:32.848216       1 connection.go:181] GRPC request: {"snapshot_id":"pvc-204b5b0f-bec0-11e9-98a6-026aef9e136c/snapshot-57aaf2aa-bec0-11e9-98a6-026aef9e136c"}
I0814 18:23:32.849316       1 connection.go:183] GRPC response: {}
I0814 18:23:32.849823       1 connection.go:184] GRPC error: rpc error: code = Unimplemented desc =
E0814 18:23:32.849842       1 snapshot_controller.go:576] checkandUpdateBoundSnapshotStatusOperation: failed to call get snapshot status to check whether snapshot is ready to use "failed to list snapshot content csi-snap-static-content: \"rpc error: code = Unimplemented desc = \""

[pavannd1]

Willing to push a PR for this change. Let me know, thanks.

[clintonk]

Thanks, @pavannd1. I can run with this one.

[korenaren]

merged.