在arkui的build.gn里增加libuv测试用例，本地测试通过

Signed-off-by: Nbayanxing <bayanxing@kaihong.com>

arkui/BUILD.gn

@@ -33,6 +33,7 @@ group("arkui") {
     "ace_napi_test:ActsAceNapiEtsTest",
     "ace_standard:ActsAceStandardTest",
     "ace_standard_video:ActsAceStandardVideoTest",
+    "libuv:ActsLibuvTestSuite",
     "libuv:libuvTest",
   ]
 }

arkui/libuv/src/ActsLibuvTestSuite.cpp

@@ -44,7 +44,7 @@ namespace OHOS {
     HWTEST_F(ActsLibuvTestSuite, TestLibuvTestCase001, Function | MediumTest | Level2)
     {
         printf("------start ActsLibuvTestSuite------\n");
-        int ret = system("/data/local/tmp/libuvruntest");
+        system("/data/local/tmp/libuvruntest");
         EXPECT_TRUE(true);
         printf("------end ActsLibuvTestSuite------\n");
     }