persistentstorage: Simplify usage of storage client, avoid unnecessary allocations #15394

Job	Run time
govulncheck	35s
setup-environment	11s
lint	2m 43s
checks	3m 19s
test-coverage	5m 29s
cross-build-collector (darwin, amd64)	45s
unittest-matrix (~1.21.3)	1m 39s
cross-build-collector (darwin, arm64)	43s
unittest-matrix (~1.20.10)	1m 24s
cross-build-collector (linux, 386)	34s
cross-build-collector (linux, amd64)	40s
cross-build-collector (linux, arm64)	1m 18s
cross-build-collector (linux, ppc64le)	1m 16s
cross-build-collector (linux, arm, 7)	1m 9s
cross-build-collector (linux, s390x)	34s
cross-build-collector (windows, 386)	44s
cross-build-collector (windows, amd64)	1m 9s
unittest	2s
	24m 14s

Provide feedback