Throw exception for unsupported values type in Alias

[mushao999]

After creating index with alias using the following request

PUT test-index
{
  "aliases": {
    "alias1": {
      "is_write_index": "true"
    }
  }
}

we got the following result for get index request:

{
  "test-index" : {
    "aliases" : {
      "alias1" : { }
    },
    "mappings" : { },
    "settings" : {   
      ...
    }
  }
}

The is_write_index field is missing because string boolean value is not supported for this filed and no warning message showed, which will mislead the users.
In #120453 I open a PR to let the createIndex API support string boolean values for is_write_index field, but @dakrone think it's better to be strict about boolean values.
So I open this PR to let the Alias class throw exception for the unsupport value type to avoid the slience swallowing of this case.

[elasticsearchmachine]

Pinging @elastic/es-data-management (Team:Data Management)

[mushao999]

ping @dakrone

[dakrone]

Thanks for opening this @mushao999, it looks pretty good. Would you mind adding a test for this to …/indices.put_alias/10_basic.yml that ensures that a bad request is returned? That way we don't accidentally undo this in the future without checking it.

[dakrone]

buildkite test this

[mushao999]

Thanks for opening this @mushao999, it looks pretty good. Would you mind adding a test for this to …/indices.put_alias/10_basic.yml that ensures that a bad request is returned? That way we don't accidentally undo this in the future without checking it.

yamlRestTest case added @dakrone

[mushao999]

Please also review this one , thanks @dakrone

[dakrone]

buildkite test this

[dakrone]

LGTM, thanks!

[mushao999]

@dakrone Cluster feature was added for BWC tests, please also enable the auto-testing for this one, thanks.