ConstraintLayout animation demos from different blog posts
- http://www.uwanttolearn.com/android/constraint-layout-animations-dynamic-constraints-ui-java-hell/
- https://proandroiddev.com/creating-awesome-animations-using-constraintlayout-and-constraintset-part-i-390cc72c5f75
- https://proandroiddev.com/creating-awesome-animations-using-constraintlayout-and-constraintset-part-2-5bbbae8ab24
- https://proandroiddev.com/creating-awesome-animations-using-constraintlayout-and-constraintset-part-3-70558f05835a
- https://android.jlelse.eu/build-awesome-animations-with-7-lines-of-code-using-constraintlayout-854e8fd3ad93