I'm submitting a ...

• bug report
• feature request
• other

Current behavior:
"Undefined" is ignored when passed down through a ng-prop-* directive.

Let's take an example:
<my-component ng-prop-text="$ctrl.text"></my-component>

this.text = 'abc'
...text is set as abc and later on
this.text = undefined;
the value of the text in my-component remains unchanged to abc

Expected / new behavior:
The value of text should be cleared in the above example (ofc you could clear with empty string but that's not the point)
ng-prop-* should accept any JS type.

AngularJS version: 1.7.5
and snapshot 1.7.6

Browser: [all]