CHW-4516 CoverageFlagInvalid

coverage flag payload requires a non-empty client_id; check the request body shape

Default message: coverage flag payload requires a non-empty client_id; check the request body shape
HTTP status: 400 (client)

Problem. A coverage-flag write returned 400. Cause. The body could not be decoded, or its client_id was empty. Fix. Resend with a non-empty client_id matching a known credential. HTTP 400.