Revert "refactor: disable strict metadata emit"

This reverts commit 70e68ff.
Fixed by angular/angular#23349.

Author: sis0k0

Diff for: nativescript-angular/tsconfig.json

@@ -29,6 +29,6 @@
     "genDir": ".",
     "skipMetadataEmit": false,
     "skipTemplateCodegen": true,
-    "strictMetadataEmit": false
+    "strictMetadataEmit": true
   }
 }