[Cronet] Use gn desc to find third party licenses on Android.

components/cronet/android/BUILD.gn

 # Copyright 2015 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("//build/buildflag_header.gni")
 import("//build/config/android/config.gni")
 import("//build/config/android/rules.gni")
 import("//build/util/version.gni")
 import("//chrome/version.gni")
 import("//testing/test.gni")
@@ skipping 799 matching lines @@
 action("generate_licenses") {
   _license_path = "$_package_dir/LICENSE"
 
   script = "//components/cronet/tools/cronet_licenses.py"
   outputs = [
     _license_path,
   ]
   args = [
     "license",
     rebase_path(_license_path, root_build_dir),
+    "--gn",
   ]
 }
 
 action("generate_javadoc") {
   script = "//components/cronet/tools/generate_javadoc.py"
   depfile = "$target_gen_dir/$target_name.d"
   outputs = [
     depfile,
   ]
   args = [
@@ skipping 62 matching lines @@
     ":cronet_package_copy_native_lib",
     ":cronet_package_copy_native_lib_unstripped",
     ":generate_javadoc",
     ":generate_licenses",
     ":jar_cronet_api_source",
     ":jar_cronet_other_source",
     ":jar_cronet_sample_source",
     ":repackage_extracted_jars",
   ]
 }