Convert some component source sets to static library

components/proximity_auth/BUILD.gn

 # Copyright 2014 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.
 
 import("//testing/test.gni")
 
-source_set("proximity_auth") {
+static_library("proximity_auth") {
   sources = [
     "authenticator.h",
     "bluetooth_connection.cc",
     "bluetooth_connection.h",
     "bluetooth_connection_finder.cc",
     "bluetooth_connection_finder.h",
     "bluetooth_throttler.h",
     "bluetooth_throttler_impl.cc",
     "bluetooth_throttler_impl.h",
     "bluetooth_util.cc",
@@ skipping 155 matching lines @@
     sources = [
       "run_all_unittests.cc",
     ]
     deps = [
       ":unit_tests",
       "//base",
       "//base/test:test_support",
     ]
   }
 }