#10939 Migrate "Session.Save" to Sync by default (#10944)

* Migrate "Session.Save" to Sync by default

* fixing unreachable code

* removing shadowing

*  whitespace changes, refactoring flow control logic

* removing unnecessary whitespace

store/storetest/mocks/SessionStore.go

@@ -147,19 +147,28 @@ func (_m *SessionStore) RemoveAllSessions() store.StoreChannel {
 }
 
 // Save provides a mock function with given fields: session
-func (_m *SessionStore) Save(session *model.Session) store.StoreChannel {
+func (_m *SessionStore) Save(session *model.Session) (*model.Session, *model.AppError) {
 	ret := _m.Called(session)
 
-	var r0 store.StoreChannel
-	if rf, ok := ret.Get(0).(func(*model.Session) store.StoreChannel); ok {
+	var r0 *model.Session
+	if rf, ok := ret.Get(0).(func(*model.Session) *model.Session); ok {
 		r0 = rf(session)
 	} else {
 		if ret.Get(0) != nil {
-			r0 = ret.Get(0).(store.StoreChannel)
+			r0 = ret.Get(0).(*model.Session)
 		}
 	}
 
-	return r0
+	var r1 *model.AppError
+	if rf, ok := ret.Get(1).(func(*model.Session) *model.AppError); ok {
+		r1 = rf(session)
+	} else {
+		if ret.Get(1) != nil {
+			r1 = ret.Get(1).(*model.AppError)
+		}
+	}
+
+	return r0, r1
 }
 
 // UpdateDeviceId provides a mock function with given fields: id, deviceId, expiresAt