tests/resolv_gold_test - fix performance-unnecessary-value-param warning

Fixes:
  packages/modules/DnsResolver/tests/resolv_gold_test.cpp:391:73: warning: the parameter 'info' is copied for each invocation but only used as a const reference; consider making it a const reference [performance-unnecessary-value-param]
    static std::string Name(::testing::TestParamInfo<GoldTestParamType> info) {
                                                                        ^
                            const                                      &

Test: builds
Bug: 153035880
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Change-Id: I619b9664ffa5f3cd8a99cb0b36e13315383630ee