consolidated BUILD files from example into one

it is also a way to test that this change works as expected.

examples/protos/BUILD → examples/BUILD

@@ -43,10 +43,24 @@ grpc_proto_library(
 
 grpc_proto_library(
     name = "helloworld",
-    srcs = ["helloworld.proto"],
+    srcs = ["protos/helloworld.proto"],
 )
 
 grpc_proto_library(
     name = "route_guide",
-    srcs = ["route_guide.proto"],
+    srcs = ["protos/route_guide.proto"],
+)
+
+cc_binary(
+    name = "greeter_client",
+    srcs = ["cpp/helloworld/greeter_client.cc"],
+    deps = ["helloworld"],
+    defines = ["BAZEL_BUILD"],
+)
+
+cc_binary(
+    name = "greeter_server",
+    srcs = ["cpp/helloworld/greeter_server.cc"],
+    deps = ["helloworld"],
+    defines = ["BAZEL_BUILD"],
 )

examples/cpp/helloworld/BUILD

-# Copyright 2017, Google Inc.
-# All rights reserved.
-#
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions are
-# met:
-#
-#     * Redistributions of source code must retain the above copyright
-# notice, this list of conditions and the following disclaimer.
-#     * Redistributions in binary form must reproduce the above
-# copyright notice, this list of conditions and the following disclaimer
-# in the documentation and/or other materials provided with the
-# distribution.
-#     * Neither the name of Google Inc. nor the names of its
-# contributors may be used to endorse or promote products derived from
-# this software without specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-cc_binary(
-    name = "greeter_client",
-    srcs = ["greeter_client.cc"],
-    deps = ["//examples/protos:helloworld"],
-    defines = ["BAZEL_BUILD"],
-)
-
-cc_binary(
-    name = "greeter_server",
-    srcs = ["greeter_server.cc"],
-    deps = ["//examples/protos:helloworld"],
-    defines = ["BAZEL_BUILD"],
-)