Title: support external_deps

Description: support external_deps

Issue: https://gitee.com/openharmony/build/issues/I6ETZJ?from=project-issue
Test：build
Signed-off-by: Ncwx1148594 <caolili14@huawei.com>

config/test/test.gni

@@ -180,6 +180,52 @@ template("unittest") {
         "-pthread",
       ]
     }
+
+    if (defined(invoker.external_deps) && invoker.external_deps != []) {
+      innersdk_dir_name = "sdk/${target_os}-${target_cpu}"
+      innersdk_base_dir = "//${innersdk_dir_name}"
+
+      component_override_map = rebase_path(
+              "${root_build_dir}/build_configs/component_override_map.json")
+      external_deps_script =
+          rebase_path("//build/templates/common/external_deps_handler.py")
+      external_deps_temp_file = "$target_gen_dir/${_part_name}__${target_name}_external_deps_temp.json"
+      arguments = [ "--external-deps" ]
+      arguments += invoker.external_deps
+      arguments += [
+        "--parts-src-flag-file",
+        rebase_path("$root_build_dir/build_configs/parts_src_flag.json",
+                    root_build_dir),
+        "--external-deps-temp-file",
+        rebase_path(external_deps_temp_file, root_build_dir),
+        "--sdk-base-dir",
+        rebase_path("${innersdk_base_dir}", root_build_dir),
+        "--sdk-dir-name",
+        "${innersdk_dir_name}",
+        "--current-toolchain",
+        current_toolchain,
+        "--innerkits-adapter-info-file",
+        rebase_path("//build/ohos/inner_kits_adapter.json", root_build_dir),
+        "--component-override-map",
+        component_override_map,
+      ]
+
+      handler_result = exec_script(external_deps_script, arguments, "string")
+      if (handler_result != "") {
+        print(handler_result)
+      }
+
+      external_deps_info = read_file(external_deps_temp_file, "json")
+      if (defined(external_deps_info.deps)) {
+        deps += external_deps_info.deps
+      }
+      if (defined(external_deps_info.libs)) {
+        libs += external_deps_info.libs
+      }
+      if (defined(external_deps_info.include_dirs)) {
+        include_dirs += external_deps_info.include_dirs
+      }
+    }
   }
 }