Update protobuf to 3.7.1 (PR 1)

Closes #7611.

Change-Id: Ib6edee142ed3cf92806f2b63d119ae11ebe51a6f

third_party/protobuf/3.7.1/.github/ISSUE_TEMPLATE/bug_report.md

@@ -0,0 +1,28 @@
+---
+name: Bug report
+about: Create a report to help us improve
+
+---
+
+**What version of protobuf and what language are you using?**
+Version: master/v3.6.0/v3.5.0 etc.
+Language: C++/Java/Python/C#/Ruby/PHP/Objective-C/Javascript
+
+**What operating system (Linux, Windows, ...) and version?**
+
+**What runtime / compiler are you using (e.g., python version or gcc version)**
+
+**What did you do?**
+Steps to reproduce the behavior:
+1. Go to '...'
+2. Click on '....'
+3. Scroll down to '....'
+4. See error
+
+**What did you expect to see**
+
+**What did you see instead?**
+
+Make sure you include information that can help us debug (full error message, exception listing, stack trace, logs).
+
+**Anything else we should know about your project / environment**

third_party/protobuf/3.7.1/.github/ISSUE_TEMPLATE/feature_request.md

@@ -0,0 +1,18 @@
+---
+name: Feature request
+about: Suggest an idea for this project
+
+---
+
+**What language does this apply to?**
+If it's a proto syntax change, is it for proto2 or proto3?
+If it's about generated code change, what programming language?
+
+**Describe the problem you are trying to solve.**
+
+**Describe the solution you'd like**
+
+**Describe alternatives you've considered**
+
+**Additional context**
+Add any other context or screenshots about the feature request here.

third_party/protobuf/3.7.1/.github/ISSUE_TEMPLATE/question.md

@@ -0,0 +1,7 @@
+---
+name: Question
+about: Questions and troubleshooting
+
+---
+
+

third_party/protobuf/3.7.1/0001-Add-dependency-on-error_prone_annotations.patch

@@ -0,0 +1,43 @@
+From d71bc7a980629afdbb1f210b7a25be6fbefffda9 Mon Sep 17 00:00:00 2001
+From: David Ostrovsky <[email protected]>
+Date: Tue, 5 Mar 2019 09:12:05 +0100
+Subject: [PATCH] Add dependency on error_prone_annotations
+
+---
+ BUILD     |  1 +
+ WORKSPACE | 10 ++++++++++
+ 2 files changed, 11 insertions(+)
+
+diff --git a/BUILD b/BUILD
+index e9e10837..5c4c2d9c 100644
+--- a/BUILD
++++ b/BUILD
+@@ -638,6 +638,7 @@ java_library(
+     visibility = ["//visibility:public"],
+     deps = [
+         "protobuf_java",
++        "//external:error_prone_annotations",
+         "//external:gson",
+         "//external:guava",
+     ],
+diff --git a/WORKSPACE b/WORKSPACE
+index 0fa64583..af3f05aa 100644
+--- a/WORKSPACE
++++ b/WORKSPACE
+@@ -74,3 +74,13 @@ bind(
+     name = "zlib",
+     actual = "@net_zlib//:zlib",
+ )
++
++maven_jar(
++    name = "error_prone_annotations_maven",
++    artifact = "com.google.errorprone:error_prone_annotations:2.3.2",
++)
++
++bind(
++    name = "error_prone_annotations",
++    actual = "@error_prone_annotations_maven//jar",
++)
+-- 
+2.20.1
+