Use the most recent 1.3.4 image for prow rc master

[saikat-royc]

What type of PR is this?

Uncomment only one /kind <> line, hit enter to put that in a new line, and remove leading whitespaces from that line:

/kind api-change
/kind bug
/kind cleanup
/kind design
/kind documentation
/kind failing-test
/kind feature
/kind flake

What this PR does / why we need it:
We have 1.3.4 as the greatest gce-pd-driver image. Switch the prow staging rc master overlay to use this image instead of the release candidate.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

Does this PR introduce a user-facing change?:

Use the most recent 1.3.4 image for prow rc master

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: saikat-royc

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• OWNERS [saikat-royc]

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