Add test_stratis_min_pool_start_invalid_unlock_method() #4892

Job	Run time
shell-checks	38s
python-based-tests	2m 21s
checks (make -f Makefile fmt-ci, 1.79.0, rustfmt)	1m 58s
stratis-cli-checks	10m 2s
checks (make -f Makefile check-typos, 1.79.0, cargo)	1m 54s
pylint	32s
stratis-min-cli-checks	1h 5m 26s
tests-with-testing-repo (HEAD, --post-test-check=verify-filesystem-symlinks --post-test-check=ver...	31m 23s
tests-with-testing-repo (v3.6.2, --highest-revision-number=6)	30m 2s
	2h 24m 16s

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