Check for deprecated/unknown environment variables #6132

Job	Run time
Lint	9m 11s
Unit Tests	8m 42s
Proxy Sanity Check	2m 19s
Unit tests with race condition detection	8m 14s
Build Unsigned Snapshot	8m 3s
Performance Tests	11m 37s
Integration Tests	-1s
Metrics Integration Tests - Official OSS Images	-1s
Upgrade Tests	-1s
Load Tests	-1s
Integration Tests - Official Plus Images	-1s
Metrics Integration Tests - Official Plus Images	-1s
Integration Tests - Official OSS Images	-1s
Lint	9m 12s
Build Unsigned Snapshot	8m 37s
Proxy Sanity Check	2m 19s
Unit tests with race condition detection	8m 14s
Unit Tests	8m 42s
Performance Tests	11m 37s
Metrics Integration Tests - Official Plus Images	0s
Metrics Integration Tests - Official OSS Images	0s
Upgrade Tests	0s
Integration Tests - Official OSS Images	0s
Load Tests	0s
Integration Tests - Official Plus Images	0s
Integration Tests	0s
	1h 36m 40s

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