Terraform considers the role and condition contents (title+description+expression) as the identifier for the binding. This means that if any part of the condition is changed out-of-band, Terraform will consider it to be an entirely different resource and will treat it as such.
Terraformはroleと条件の内容（title+description+expression）をバインディングの識別子とみなしているので、expressionを変更すると破壊的変更になる
