Fix the order that `SyncConfig`'s members are declared in so that they match the order of the constructor arguments.
Fix the order that `SyncConfig`'s members are declared in so that they
match the order of the constructor arguments.

`validate_sync_history` is not intended to be provided by clients so it
is omitted from the constructor. This means it must be the last member
in the struct.

realm/realm-core,realm/realm-core,realm/realm-object-store,realm/realm-object-store,realm/realm-object-store,realm/realm-core,realm/realm-core,realm/realm-core,realm/realm-core,realm/realm-core