Injecting AngularFireAuth to component triggers ChangeDetection continuously #1544

Version info

Angular: 5.2.0

Firebase: 4.12.1

AngularFire: 5.0.0-rc.6

Other (e.g. Ionic/Cordova, Node, browser, operating system): Windows 10, Google Chrome 65,npm: '5.6.0', node: '8.9.1'

How to reproduce these conditions

1. Inject AngularFireAuth into the AppComponent.
2. Create get method for a property. Log a message to console in the method.
3. Refer the property in the template using {{}}
4. View the application in chrome, observe console using developer tools

The log message in the get method is printed continuously as if in a loop. This behavior disappears if the constructor injection of AngularFireAuth is removed.

Failing test unit, Plunkr, or JSFiddle demonstrating the problem

https://embed.plnkr.co/S3cm7hpJImTtaTSa9Om0/

Steps to set up and reproduce
Create new Angular app. Add AngularFire2 and Firebase modules.

Sample data and security rules
None

None

Debug output

Please see attachment.

Expected behavior

The get method is called only once. The injected AngularFireAuth does not trigger ChangeDetection in Angular.

Actual behavior

The log message in the get method is printed continuously as if in a loop due to ChangeDetection being triggered.

localhost-1522757258645.log