Restore `endWritable` default.
Restore `endWritable` default.

No release had been done since it was changed.

cdapio/ui-schema-parser,mtth/avsc,mtth/avsc,cdapio/ui-schema-parser,cdapio/ui-schema-parser,cdapio/ui-schema-parser,mtth/avsc,cdapio/ui-schema-parser,mtth/avsc,mtth/avsc