Spanner throws error creating Foreign Keys referring the same column concurrently

[Deep1998]

When multiple create FK requests are sent to spanner where the referenced column is same and require internal index creation, spanner throws an error of the form The schema change adding index IDX_contract_ContractID_U_09F242C8CD7BD34 for foreign key FK_contract_sku_3 must finish before adding foreign key FK_fingerprint_contract_2.