Convert some component source sets to static library

components/network_session_configurator/BUILD.gn

 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # GYP version:
 # components/components.gyp:network_session_configurator
-source_set("network_session_configurator") {
+static_library("network_session_configurator") {
   sources = [
     "network_session_configurator.cc",
     "network_session_configurator.h",
   ]
 
   public_deps = [
     ":switches",
     "//base",
     "//net",
   ]
 
   deps = [
     "//components/data_reduction_proxy/core/common",
     "//components/variations",
     "//components/version_info",
   ]
 }
 
 # GYP version:
 # components/components.gyp:network_session_configurator_switches
-source_set("switches") {
+static_library("switches") {
   sources = [
     "switches.cc",
     "switches.h",
   ]
 }
 
 source_set("unit_tests") {
   testonly = true
   sources = [
     "network_session_configurator_unittest.cc",
   ]
   deps = [
     ":network_session_configurator",
     "//base/test:test_support",
     "//components/variations:variations",
     "//testing/gtest",
   ]
 }