Revert "Improve protobuf support (#2513)" (#2665)

Summary:
This reverts commit efd75ea435.

Sorry hbmartin! We're running into Kotlin compatibility problems. Your latest library release isn't compatible with Kotlin 1.3 and we can't upgrade just yet because Litho hasn't been able to release in a while. :(

Pull Request resolved: https://github.com/facebook/flipper/pull/2665

Test Plan: _eyes

Differential Revision: D30189360

Pulled By: passy

fbshipit-source-id: c1edbbc496742938579f4e2032a78debe08fcc26

desktop/plugins/public/network/ProtobufDefinitionsRepository.tsx

@@ -63,10 +63,6 @@ export class ProtobufDefinitionsRepository {
     }
   }
 
-  public hasDefinition(method: string, path: string): boolean {
-    return this.rawDefinitions.hasOwnProperty(this.key(method, path));
-  }
-
   private generateRoots(key: string) {
     if (key in this.cachedDecodedDefinitions) {
       return;