Replace most uses of asset_location with android_assets() template

net/BUILD.gn

Index: net/BUILD.gn
diff --git a/net/BUILD.gn b/net/BUILD.gn
index 7963a0a0cfb4b69422a84ae887b9766a5ec22132..6d9c9bc383d13dfad3f825aefd7e2d9801c56666 100644
--- a/net/BUILD.gn
+++ b/net/BUILD.gn
@@ -1208,21 +1208,6 @@ if (is_android) {
     ]
     jni_package = "net/test"
   }
-
-  _net_unittests_apk_assets_dir = "$root_out_dir/net_unittests_apk/assets"
-
-  copy_ex("copy_net_unittests_apk_assets") {
-    clear_dir = true
-    dest = _net_unittests_apk_assets_dir
-
-    if (v8_use_external_startup_data) {
-      renaming_sources = v8_external_startup_data_renaming_sources
-      renaming_destinations = v8_external_startup_data_renaming_destinations
-      deps = [
-        "//v8",
-      ]
-    }
-  }
 }
 
 if (is_android || is_linux) {
@@ -1616,7 +1601,7 @@ test("net_unittests") {
       "//net/android:net_javatests",
       "//net/android:net_java_test_support",
       "//net/android:net_unittests_apk_resources",
-      ":copy_net_unittests_apk_assets",
+      "//v8:v8_external_startup_data_assets",
     ]
     android_manifest = "//net/android/unittest_support/AndroidManifest.xml"
     sources -= [
@@ -1633,7 +1618,6 @@ test("net_unittests") {
     set_sources_assignment_filter([])
     sources += [ "base/address_tracker_linux_unittest.cc" ]
     set_sources_assignment_filter(sources_assignment_filter)
-    apk_asset_location = _net_unittests_apk_assets_dir
     isolate_file = "net_unittests.isolate"
   }