废弃字段上的sharing属性，调整为write_requires_master_read 【boolean】
Created by: baozhoutao
Sets the minimum sharing access level required on the master record to create, edit, or delete child records. This field applies only to master-detail or junction object custom field types. true—Allows users with “Read” access to the master record permission to create, edit, or delete child records. This setting makes sharing less restrictive. false—Allows users with “Read/Write” access to the master record permission to create, edit, or delete child records. This setting is more restrictive than true, and is the default value. For junction objects, the most restrictive access from the two parents is enforced. For example, if you set to true on both master-detail fields, but users have “Read” access to one master record and “Read/Write” access to the other master record, users won't be able to create, edit, or delete child records.