In version 10, undecorated base classes that use Angular features need
to be decorated explicitly with `@Directive()`. Additionally, derived
classes of abstract directives need to be decorated.
The migration already handles this for undecorated classes that are
not explicitly decorated, but since in V9, abstract directives can be
used, we also need to handle this for explicitly decorated abstract
directives. e.g.
```
@Directive()
export class Base {...}
// needs to be decorated by migration when updating from v9 to v10
export class Wrapped extends Base {}
@Component(...)
export class Cmp extends Wrapped {}
```
PR Close#35339
c24ad560fa