fix message notification for archived conversations

fixes VICE-4379
flag=react_inbox
test plan:
- have a conversation between 2 users
- user A should archive the conversation
- user B should message user A in the same convo
- user A should see the archived convo back in the list,
  with a notification

Change-Id: Iebc5896ac7bd90957dc8cfd0d287977580634504
Reviewed-on: https://gerrit.instructure.com/c/canvas-lms/+/351534
Tested-by: Service Cloud Jenkins <svc.cloudjenkins@instructure.com>
Reviewed-by: Omar Soto-Fortuño <omar.soto@instructure.com>
Reviewed-by: Balint Kartyas <balint.kartyas@instructure.com>
QA-Review: Dora Csolakov <dora.csolakov@instructure.com>
Product-Review: Ádám Molnár <adam.molnar@instructure.com>

spec/selenium/conversations/conversations_spec.rb

@@ -175,6 +175,23 @@ describe "conversations new" do
         expect(f("body")).not_to contain_jqcss "div[data-testid='conversation']"
       end
 
+      it "archives convo then checks availability after a new message" do
+        get "/conversations"
+        f("div[data-testid='conversation']").click
+        wait_for_ajaximations
+        f("button[data-testid='more-options']").click
+        fj("li:contains('Archive')").click
+        driver.switch_to.alert.accept
+        wait_for_ajaximations
+        expect(f("body")).not_to contain_jqcss "div[data-testid='conversation']"
+
+        @convo.add_message(@s[0], "second Message")
+        @convo.save!
+        get "/conversations"
+        wait_for_ajaximations
+        expect(f("body")).to contain_jqcss "div[data-testid='conversation']"
+      end
+
       it "does not have archive options button when in sent scope" do
         get "/conversations#filter=type=sent"
         f("div[data-testid='conversation']").click

ui/features/inbox/react/containers/CanvasInbox.jsx

@@ -307,7 +307,6 @@ const CanvasInbox = () => {
         variables: {
           conversationIds: selectedConversations.map(convo => convo._id),
           workflowState: 'archived',
-          subscribed: false,
         },
       })
     } else {