refactor(angular): import map from rxjs correctly

The rxjs docs gives best practices : https://rxjs.dev/guide/importing#new-in-rxjs-v720

Signed-off-by: backtrack5r3 <flennertom@gmail.com>

Author: tomflenner

internal/cmd/testdata/success_angular.golden

@@ -27,7 +27,7 @@ import {
   FeatureFlagService,
   JsonValue,
 } from '@openfeature/angular-sdk';
-import { map } from 'rxjs/operators';
+import { map } from 'rxjs';
 import { Observable } from 'rxjs';
 
 // ============================================================================

internal/generators/angular/angular.tmpl

@@ -27,7 +27,7 @@ import {
   FeatureFlagService,
   JsonValue,
 } from '@openfeature/angular-sdk';
-import { map } from 'rxjs/operators';
+import { map } from 'rxjs';
 import { Observable } from 'rxjs';
 
 // ============================================================================