dashboard/app: add spanner Jobs.Correct field #18745

Job	Run time
aux	4m 0s
old	6m 56s
dashboard	1m 59s
race	7m 17s
race_dashboard	3m 11s
arch (presubmit_arch_netbsd)	3m 54s
arch (presubmit_arch_linux)	11m 7s
gvisor	4m 1s
arch (presubmit_arch_openbsd)	3m 57s
arch (presubmit_arch_freebsd)	6m 32s
arch (presubmit_arch_darwin)	3m 24s
arch (presubmit_arch_windows)	3m 45s
build	3m 15s
arch (presubmit_arch_executor)	3m 20s
	1h 6m 38s

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