Fix issue where some threads were invisibly unread.

Problem 1: We weren't marking threads read when we shared into them.
Problem 2: We hid the unread status of threads whose last message was
outgoing.

This addresses both. It's possible that 'fixing' problem 2 could result
in more threads being marked as read, but really that should just make
us aware so we can properly mark the thread as read.

app/src/main/java/org/thoughtcrime/securesms/conversationlist/ConversationListItem.java

@@ -462,7 +462,7 @@ public final class ConversationListItem extends ConstraintLayout implements Bind
   }
 
   private void setUnreadIndicator(ThreadRecord thread) {
-    if ((thread.isOutgoing() && !thread.isForcedUnread()) || thread.isRead()) {
+    if (thread.isRead()) {
       unreadIndicator.setVisibility(View.GONE);
       return;
     }

app/src/main/java/org/thoughtcrime/securesms/sharing/MultiShareSender.java

@@ -156,6 +156,10 @@ public final class MultiShareSender {
         results.add(new MultiShareSendResult(recipientSearchKey, MultiShareSendResult.Type.SUCCESS));
       }
 
+      if (!recipientSearchKey.isStory()) {
+        SignalDatabase.threads().setRead(threadId, true);
+      }
+
       // XXX We must do this to avoid sending out messages to the same recipient with the same
       //     sentTimestamp. If we do this, they'll be considered dupes by the receiver.
       ThreadUtil.sleep(5);