netty: Add Bazel target similar to netty-shaded

See census-instrumentation/opencensus-java#1963

netty/BUILD.bazel

@@ -27,3 +27,11 @@ java_library(
         "@io_perfmark_perfmark_api//jar",
     ],
 )
+
+# Not actually shaded, but mirrors the shaded dependencies included in the
+# artifact on Maven Central for usage with maven_install's override_targets.
+java_library(
+    name = "shaded",
+    visibility = ["//visibility:public"],
+    exports = ["//netty/shaded"],
+)

netty/shaded/BUILD.bazel

@@ -0,0 +1,10 @@
+# Publicly exposed in //netty package. Purposefully does not export any symbols.
+java_library(
+    name = "shaded",
+    visibility = ["//netty:__pkg__"],
+    runtime_deps = [
+        "//netty",
+        "@io_netty_netty_tcnative_boringssl_static//jar",
+        "@io_netty_netty_transport_native_epoll//jar",
+    ],
+)

repositories.bzl

@@ -25,6 +25,7 @@ def grpc_java_repositories(
         omit_io_netty_buffer = False,
         omit_io_netty_common = False,
         omit_io_netty_transport = False,
+        omit_io_netty_transport_native_epoll = False,
         omit_io_netty_codec = False,
         omit_io_netty_codec_socks = False,
         omit_io_netty_codec_http = False,
@@ -84,6 +85,8 @@ def grpc_java_repositories(
         io_netty_common()
     if not omit_io_netty_transport:
         io_netty_transport()
+    if not omit_io_netty_transport_native_epoll:
+        io_netty_transport_native_epoll()
     if not omit_io_netty_codec:
         io_netty_codec()
     if not omit_io_netty_codec_socks:
@@ -383,6 +386,15 @@ def io_netty_transport():
         licenses = ["notice"],  # Apache 2.0
     )
 
+def io_netty_transport_native_epoll():
+    jvm_maven_import_external(
+        name = "io_netty_netty_transport_native_epoll",
+        artifact = "io.netty:netty-transport-native-epoll:jar:linux-x86_64:4.1.38.Final",
+        server_urls = ["http://central.maven.org/maven2"],
+        artifact_sha256 = "7933467e1cfc37bc6fb3f22af471ed69cb66bebaceab73d2041772bb6a38218a",
+        licenses = ["notice"],  # Apache 2.0
+    )
+
 def io_opencensus_api():
     jvm_maven_import_external(
         name = "io_opencensus_opencensus_api",