5.3.0-rc.4

Final candidate for 5.3.0.

• AngularFireAnalytics and AngularFireRemoteConfig should be safe in non-browser environments (mostly noop due to lack of support in the Firebase libraries, but should not cause runtime exceptions)
• ScreenTrackingService should now be more reliable in reporting your component's selector (as screen_name), especially in AOT mode.
• To better facilitate debugging, ScreenTrackingService will console log screen_view events when DEBUG_MODE is enabled.

Please test that screen_class attribute is correct tracking your component's selector in Google Analytics for the ScreenTrackingService both against AOT and JIT. There's some hard to test code here. Report your experience on #2187