refactor(ivy): migrate ɵɵ prefix back to Δ (#30362)

Now that issues are resolved with Closure compiler, we can move back to our desired prefix of `Δ`.

PR Close #30362

packages/compiler-cli/src/metadata/bundler.ts

@@ -423,7 +423,7 @@ export class MetadataBundler {
         result[key] = this.convertFunction(moduleName, value);
       } else if (isMetadataSymbolicCallExpression(value)) {
         // Class members can also contain static members that call a function with module
-        // references. e.g. "static ngInjectableDef = ɵɵdefineInjectable(..)". We also need to
+        // references. e.g. "static ngInjectableDef = ΔdefineInjectable(..)". We also need to
         // convert these module references because otherwise these resolve to non-existent files.
         result[key] = this.convertValue(moduleName, value);
       } else {

packages/compiler-cli/src/ngtsc/imports/src/core.ts

@@ -48,15 +48,15 @@ export class NoopImportRewriter implements ImportRewriter {
  * which they're exported from r3_symbols.
  */
 const CORE_SUPPORTED_SYMBOLS = new Map<string, string>([
-  ['ɵɵdefineInjectable', 'ɵɵdefineInjectable'],
-  ['ɵɵdefineInjector', 'ɵɵdefineInjector'],
-  ['ɵɵdefineNgModule', 'ɵɵdefineNgModule'],
-  ['ɵɵsetNgModuleScope', 'ɵɵsetNgModuleScope'],
-  ['ɵɵinject', 'ɵɵinject'],
+  ['ΔdefineInjectable', 'ΔdefineInjectable'],
+  ['ΔdefineInjector', 'ΔdefineInjector'],
+  ['ΔdefineNgModule', 'ΔdefineNgModule'],
+  ['ΔsetNgModuleScope', 'ΔsetNgModuleScope'],
+  ['Δinject', 'Δinject'],
   ['ɵsetClassMetadata', 'setClassMetadata'],
-  ['ɵɵInjectableDef', 'ɵɵInjectableDef'],
-  ['ɵɵInjectorDef', 'ɵɵInjectorDef'],
-  ['ɵɵNgModuleDefWithMeta', 'ɵɵNgModuleDefWithMeta'],
+  ['ΔInjectableDef', 'ΔInjectableDef'],
+  ['ΔInjectorDef', 'ΔInjectorDef'],
+  ['ΔNgModuleDefWithMeta', 'ΔNgModuleDefWithMeta'],
   ['ɵNgModuleFactory', 'NgModuleFactory'],
 ]);