Don't allow changing answers if the poll has started

Just like we did with questions.

spec/controllers/admin/poll/questions/answers_controller_spec.rb

@@ -0,0 +1,88 @@
+require "rails_helper"
+
+describe Admin::Poll::Questions::AnswersController, :admin do
+  let(:current_question) { create(:poll_question, poll: create(:poll)) }
+  let(:future_question) { create(:poll_question, poll: create(:poll, :future)) }
+
+  describe "POST create" do
+    it "is not possible for an already started poll" do
+      post :create, params: {
+        poll_question_answer: {
+          translations_attributes: {
+            "0" => {
+              locale: "en",
+              title: "Answer from started poll"
+            }
+          }
+        },
+        question_id: current_question
+      }
+
+      expect(flash[:alert]).to eq "You do not have permission to carry out the action 'create' on Answer."
+      expect(Poll::Question::Answer.count).to eq 0
+    end
+
+    it "is possible for a not started poll" do
+      post :create, params: {
+        poll_question_answer: {
+          translations_attributes: {
+            "0" => {
+              locale: "en",
+              title: "Answer from future poll"
+            }
+          }
+        },
+        question_id: future_question
+      }
+
+      expect(response).to redirect_to admin_question_path(future_question)
+      expect(Poll::Question::Answer.last.title).to eq "Answer from future poll"
+      expect(Poll::Question::Answer.count).to eq 1
+    end
+  end
+
+  describe "PATCH update" do
+    it "is not possible for an already started poll" do
+      current_answer = create(:poll_question_answer, question: current_question, title: "Sample title")
+
+      patch :update, params: {
+        poll_question_answer: {
+          translations_attributes: {
+            "0" => {
+              locale: "en",
+              title: "New title",
+              id: current_answer.translations.first.id
+            }
+          }
+        },
+        question_id: current_question,
+        id: current_answer
+      }
+
+      expect(flash[:alert]).to eq "You do not have permission to carry out the action 'update' on Answer."
+      expect(current_answer.reload.title).to eq "Sample title"
+    end
+
+    it "is possible for a not started poll" do
+      future_answer = create(:poll_question_answer, question: future_question)
+
+      patch :update, params: {
+        poll_question_answer: {
+          translations_attributes: {
+            "0" => {
+              locale: "en",
+              title: "New title",
+              id: future_answer.translations.first.id
+            }
+          }
+        },
+        question_id: future_question,
+        id: future_answer
+      }
+
+      expect(response).to redirect_to admin_question_path(future_question)
+      expect(flash[:notice]).to eq "Changes saved"
+      expect(future_answer.reload.title).to eq "New title"
+    end
+  end
+end