PLT-3462 Add the ability to clear push notifications after channel is viewed (#3834)

* Add the ability to clear push notifications after channel is viewed

* Fix race condition between updating the mention count and reading it when sending push notifications

model/session.go

@@ -6,6 +6,7 @@ package model
 import (
 	"encoding/json"
 	"io"
+	"strings"
 )
 
 const (
@@ -109,6 +110,11 @@ func (me *Session) GetTeamByTeamId(teamId string) *TeamMember {
 	return nil
 }
 
+func (me *Session) IsMobileApp() bool {
+	return len(me.DeviceId) > 0 &&
+		(strings.HasPrefix(me.DeviceId, PUSH_NOTIFY_APPLE+":") || strings.HasPrefix(me.DeviceId, PUSH_NOTIFY_ANDROID+":"))
+}
+
 func SessionsToJson(o []*Session) string {
 	if b, err := json.Marshal(o); err != nil {
 		return "[]"