Check remote translations locales at runtime

We were evaluating its value when the server starts. On production
enviroments, that could mean weeks or months before the available
locales are checked again, and so it would be possible to use a list
which is no longer in sync with the list provided by microsoft.

app/models/remote_translation.rb

@@ -4,7 +4,7 @@ class RemoteTranslation < ApplicationRecord
   validates :remote_translatable_id, presence: true
   validates :remote_translatable_type, presence: true
   validates :locale, presence: true
-  validates :locale, inclusion: { in: RemoteTranslations::Microsoft::AvailableLocales.available_locales }
+  validates :locale, inclusion: { in: ->(_) { RemoteTranslations::Microsoft::AvailableLocales.available_locales }}
   validate :already_translated_resource
   after_create :enqueue_remote_translation
 

spec/models/remote_translation_spec.rb

@@ -37,6 +37,18 @@ describe RemoteTranslation do
     expect(remote_translation).not_to be_valid
   end
 
+  it "checks available locales dynamically" do
+    allow(RemoteTranslations::Microsoft::AvailableLocales)
+      .to receive(:available_locales).and_return(["en"])
+
+    expect(remote_translation).not_to be_valid
+
+    allow(RemoteTranslations::Microsoft::AvailableLocales)
+      .to receive(:available_locales).and_return(["es"])
+
+    expect(remote_translation).to be_valid
+  end
+
   describe "#enqueue_remote_translation", :delay_jobs do
     it "after create enqueue Delayed Job" do
       expect { remote_translation.save }.to change { Delayed::Job.count }.by(1)