refactor: add enableIvy: true until FW flips it on by default

Author: alan-agius4

packages/schematics/angular/workspace/files/tsconfig.json.template

@@ -20,6 +20,7 @@
     ]
   },
   "angularCompilerOptions": {
+    "enableIvy": true,
     "fullTemplateTypeCheck": true,
     "strictInjectionParameters": true
   }

tests/angular_devkit/build_angular/hello-world-app-ivy/tsconfig.json

@@ -17,5 +17,8 @@
       "es2017",
       "dom"
     ]
+  },
+  "angularCompilerOptions": {
+    "enableIvy": true
   }
 }

tests/angular_devkit/build_ng_packagr/ng-packaged-ivy/tsconfig.json

@@ -16,5 +16,8 @@
       "es2017",
       "dom"
     ]
+  },
+  "angularCompilerOptions": {
+    "enableIvy": true
   }
 }