fix(forms): changes to status not always being emitted to statusChanges observable for async validators. (#42553)

When a FormControl, FormArray, or FormGroup is first constructed, if an async validator is attached, the `statusChanges` observable should receive a message when the validator complete (i.e. pending -> valid/invalid). If the validator was provided as part of the constructor options, it was not fired at construction time, which is fixed in this PR.

Fixes #35309.

PR Close #42553

packages/forms/src/model.ts

@@ -1167,7 +1167,7 @@ export class FormControl extends AbstractControl {
       // `VALID` or `INVALID`.
       // The status should be broadcasted via the `statusChanges` observable, so we set `emitEvent`
       // to `true` to allow that during the control creation process.
-      emitEvent: !!asyncValidator
+      emitEvent: !!this.asyncValidator
     });
   }
 
@@ -1433,7 +1433,7 @@ export class FormGroup extends AbstractControl {
       // If `asyncValidator` is present, it will trigger control status change from `PENDING` to
       // `VALID` or `INVALID`. The status should be broadcasted via the `statusChanges` observable,
       // so we set `emitEvent` to `true` to allow that during the control creation process.
-      emitEvent: !!asyncValidator
+      emitEvent: !!this.asyncValidator
     });
   }
 
@@ -1887,7 +1887,7 @@ export class FormArray extends AbstractControl {
       // `VALID` or `INVALID`.
       // The status should be broadcasted via the `statusChanges` observable, so we set `emitEvent`
       // to `true` to allow that during the control creation process.
-      emitEvent: !!asyncValidator
+      emitEvent: !!this.asyncValidator
     });
   }