If the validator is bound to be `null` then no validation occurs and
attribute is not added to DOM.
For every validator type different PR will be raised as discussed in
https://github.com/angular/angular/pull/42378.
Closes#42267.
PR Close#42565
* No longer builds the example e2e tests using "tsc". The examples are now built with Bazel and can therefore be built with Ivy by using the `--define=compile=aot` switch.
* No longer runs the example e2e tests using the protractor CLI. example e2e tests are executed with the Bazel protractor rule and can therefore run incrementally.
NOTE: Unit tests found within the examples are still running within the legacy jobs.
PR Close#28402