As with regular Angular components, Angular elements are expected to
have their views update when inputs change.
Previously, Angular Elements views were not updated if the underlying
component used the `OnPush` change detection strategy.
This commit fixes this by calling `markForCheck()` on the component
view's `ChangeDetectorRef`.
NOTE:
This is similar to how `@angular/upgrade` does it:
3236ae0ee1/packages/upgrade/src/common/src/downgrade_component_adapter.ts (L146).
Fixes#38948
PR Close#39452
Previously, the project used for running integration tests for Angular
Elements declared a component that used `ShadowDom` for view
encopsulation, but it did not include any tests to verify that the view
was updated correctly.
This commit adds the missing tests.
PR Close#39452
