Promote Dutch and Russian to Beta, v5.22 (mattermost#4957)

* Promote Dutch and Russian to Beta, v5.22

Both have exceeded 90% in translation server https://translate.mattermost.com/projects/mattermost/

Big shoutouts to Tom De Moor and flynbit!

* Update schema_admin_settings.test.jsx.snap

components/admin_console/__snapshots__/schema_admin_settings.test.jsx.snap

@@ -315,7 +315,7 @@ exports[`components/admin_console/SchemaAdminSettings should match snapshot with
  },
  Object {
  "order": 5,
- "text": "Nederlands (Alpha)",
+ "text": "Nederlands (Beta)",
  "value": "nl",
  },
  Object {
@@ -340,7 +340,7 @@ exports[`components/admin_console/SchemaAdminSettings should match snapshot with
  },
  Object {
  "order": 10,
- "text": "Pусский (Alpha)",
+ "text": "Pусский (Beta)",
  "value": "ru",
  },
  Object {
@@ -429,7 +429,7 @@ exports[`components/admin_console/SchemaAdminSettings should match snapshot with
  },
  Object {
  "order": 5,
- "text": "Nederlands (Alpha)",
+ "text": "Nederlands (Beta)",
  "value": "nl",
  },
  Object {
@@ -454,7 +454,7 @@ exports[`components/admin_console/SchemaAdminSettings should match snapshot with
  },
  Object {
  "order": 10,
- "text": "Pусский (Alpha)",
+ "text": "Pусский (Beta)",
  "value": "ru",
  },
  Object {

i18n/i18n.jsx

@@ -82,7 +82,7 @@ const languages = {
  },
  nl: {
  value: 'nl',
- name: 'Nederlands (Alpha)',
+ name: 'Nederlands (Beta)',
  order: 5,
  url: nl,
  },
@@ -106,7 +106,7 @@ const languages = {
  },
  ru: {
  value: 'ru',
- name: 'Pусский (Alpha)',
+ name: 'Pусский (Beta)',
  order: 10,
  url: ru,
  },