refactor(ivy): use ɵɵ instead of Δ for now (#29850)

The `Δ` caused issue with other infrastructure, and we are temporarily
changing it to `ɵɵ`.

This commit also patches ts_api_guardian_test and AIO to understand `ɵɵ`.

PR Close #29850

packages/core/src/di/injection_token.ts

@@ -8,7 +8,7 @@
 
 import {Type} from '../interface/type';
 
-import {ΔdefineInjectable} from './interface/defs';
+import {ɵɵdefineInjectable} from './interface/defs';
 
 /**
  * Creates a token that can be used in a DI Provider.
@@ -67,7 +67,7 @@ export class InjectionToken<T> {
       // We are using it to assign `-1` which is used to identify `Injector`.
       (this as any).__NG_ELEMENT_ID__ = options;
     } else if (options !== undefined) {
-      this.ngInjectableDef = ΔdefineInjectable({
+      this.ngInjectableDef = ɵɵdefineInjectable({
         providedIn: options.providedIn || 'root',
         factory: options.factory,
       });