Revert "Add code sharing sample (#1444)" (#1464)

This reverts commit fc6222ebc8.

code_sharing/server/test/server_test.dart

@@ -1,40 +0,0 @@
-import 'dart:convert';
-import 'dart:io';
-
-import 'package:http/http.dart';
-import 'package:test/test.dart';
-
-// Manual test:
-// $ dart bin/server.dart
-// $ curl -X POST -d '{"by": 1}' -H "Content-Type: application/json" localhost:8080/
-
-void main() {
-  final port = '8080';
-  final host = 'http://0.0.0.0:$port';
-  late Process p;
-
-  setUp(() async {
-    p = await Process.start(
-      'dart',
-      ['run', 'bin/server.dart'],
-      environment: {'PORT': port},
-    );
-    // Wait for server to start and print to stdout.
-    await p.stdout.first;
-  });
-
-  tearDown(() => p.kill());
-
-  test('Increment', () async {
-    final response = await post(Uri.parse('$host/'), body: '{"by": 1}');
-    expect(response.statusCode, 200);
-    expect(response.body, '{"value":1}');
-  });
-
-  test('Get', () async {
-    final response = await get(Uri.parse('$host/'));
-    expect(response.statusCode, 200);
-    final resp = json.decode(response.body) as Map;
-    expect(resp.containsKey('value'), true);
-  });
-}