Remove UiSettings client side validation

[mshustov]

We added server-side validation for UiSettings to cover cases when settings changed via API & kibana.yml config.

kibana/src/core/types/ui_settings.ts

Line 82 in dd7531d

schema: Type<T>;

I managed to find only two last plugins relying on the deprecated client-side validation:

• file_upload plugin

  kibana/x-pack/plugins/file_upload/server/plugin.ts

  Line 43 in 81b4693

  regexString: '\\d+[mMgG][bB]',

  @elastic/kibana-gis
• reporting plugin

  kibana/x-pack/plugins/reporting/server/plugin.ts

  Line 65 in 6908fe7

  length: kbToBase64Length(200),

  @elastic/kibana-reporting-services

Plugins should migrate to the server-side validation.
The core should remove legacy client-side validation support.

[elasticmachine]

Pinging @elastic/kibana-platform (Team:Platform)

[peteharverson]

Note the regexString validation has been moved from the ml plugin to the file_upload plugin and is now in x-pack/plugins/file_upload/server/plugin.ts.

[mshustov]

@peteharverson thank you, I updated the issue description.