move custom-file-picker-config into agent-runtime #3924

Job	Run time
build-and-check	2m 32s
test-backend	2m 18s
test-packages/agent-runtime	33s
test-cli	32s
test-.agents	33s
test-common	29s
test-integration-cli	29s
test-npm-app	32s
test-integration-.agents	29s
test-web	37s
test-integration-web	31s
test-integration-packages/agent-runtime	34s
test-integration-npm-app	32s
test-integration-backend	40s
test-integration-common	29s
	11m 50s

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