[ObjC ARC] Converts ios/chrome/test/earl_grey:ios_chrome_device_check_egtests to ARC.

ios/chrome/test/earl_grey/chrome_ios_eg_test.gni

Index: ios/chrome/test/earl_grey/chrome_ios_eg_test.gni
diff --git a/ios/chrome/test/earl_grey/chrome_ios_eg_test.gni b/ios/chrome/test/earl_grey/chrome_ios_eg_test.gni
index 521856d2c888ec9045fc303ed18deeeaa6c0f986..7623cb51f52b0cc46150bdbc22ffb1bd2872847a 100644
--- a/ios/chrome/test/earl_grey/chrome_ios_eg_test.gni
+++ b/ios/chrome/test/earl_grey/chrome_ios_eg_test.gni
@@ -150,3 +150,7 @@ template("chrome_ios_eg_test") {
     }
   }
 }
+
+set_defaults("chrome_ios_eg_test") {
+  configs = default_executable_configs
+}