PLT-7130 adding more generic push notificaiton message. (#7044)

* PLT-7130 adding more generic push notificaiton message.

* Fixing strings

app/notification.go

@@ -501,6 +501,15 @@ func sendPushNotification(post *model.Post, user *model.User, channel *model.Cha
 		} else {
 			msg.Message = senderName + userLocale("api.post.send_notifications_and_forget.push_in") + channelName + ": " + model.ClearMentionTags(post.Message)
 		}
+	} else if *utils.Cfg.EmailSettings.PushNotificationContents == model.GENERIC_NO_CHANNEL_NOTIFICATION {
+		if channel.Type == model.CHANNEL_DIRECT {
+			msg.Category = model.CATEGORY_DM
+			msg.Message = senderName + userLocale("api.post.send_notifications_and_forget.push_message")
+		} else if wasMentioned || channel.Type == model.CHANNEL_GROUP {
+			msg.Message = senderName + userLocale("api.post.send_notifications_and_forget.push_mention_no_channel")
+		} else {
+			msg.Message = senderName + userLocale("api.post.send_notifications_and_forget.push_non_mention_no_channel")
+		}
 	} else {
 		if channel.Type == model.CHANNEL_DIRECT {
 			msg.Category = model.CATEGORY_DM