Add protobuf support to network inspector (#2080)

Summary:
Protobuf based APIs are becoming more common (i.e. gRPC) but are difficult to inspect. Unlike plain text data formats (JSON), Protobuf calls transmit binary data requiring the format to be known ahead of time, making ad-hoc inspection impossible. This PR allows for those format definitions (messages in protobuf terminology) to be transmitted from the client to the network inspector plugin. These definitions are then imported into ProtobufJS which enables the binary data transmitted to be inspected as easily as JSON data.

See Retrofit PR in https://github.com/facebook/flipper/pull/2084

## Changelog

* Add ProtobufJS library to network plugin
* New `ProtobufFormatter` UI in `RequestDetails`
* `ProtobufDefinitionsRepository` to cache and load protobuf defintions
* `addProtobufDefinitions` call in the Android network plugin

Pull Request resolved: https://github.com/facebook/flipper/pull/2080

Test Plan: ![screenshot](https://user-images.githubusercontent.com/745166/111652068-001a5e80-87c4-11eb-8c94-e19b46dd074c.png)

Reviewed By: mweststrate

Differential Revision: D27507451

Pulled By: passy

fbshipit-source-id: 586d891b74f2b17d28fe7a2a99074da755851f38

android/plugins/network/src/main/java/com/facebook/flipper/plugins/network/NetworkFlipperPlugin.java

@@ -127,6 +127,19 @@ public class NetworkFlipperPlugin extends BufferingFlipperPlugin implements Netw
     job.run();
   }
 
+  public void addProtobufDefinitions(
+      final String baseUrl, final FlipperArray callNestedMessagesPayloads) {
+    (new ErrorReportingRunnable(getConnection()) {
+          @Override
+          protected void runOrThrow() throws Exception {
+            send(
+                "addProtobufDefinitions",
+                new FlipperObject.Builder().put(baseUrl, callNestedMessagesPayloads).build());
+          }
+        })
+        .run();
+  }
+
   private String toBase64(@Nullable byte[] bytes) {
     if (bytes == null) {
       return null;