message: test: remove CONSTRUCT_ON_FIRST_USE from ads_integration_test
  This string constant is not constant when ads_integration_test is parameterized on delta/SotW.
  Risk Level: none
  Testing: test-only change
  Doc Changes: n /a
  Release Notes:  n/a
diff: #include "test/integration/http_integration.h"
  namespace Envoy {
  -static const std::string& AdsIntegrationConfig() {
  - CONSTRUCT_ON_FIRST_USE(std::string, R"EOF(
  +static std::string AdsIntegrationConfig() {
  + // Note: do not use CONSTRUCT_ON_FIRST_USE here!
  + return R"EOF(
  dynamic_resources:
  lds_config: {ads: {}}
  cds_config: {ads: {}}
  @@ -38,7 +39,7 @@ admin:
  socket_address:
  address: 127.0.0.1
  port_value: 0
  -)EOF");
  +)EOF";
  }
  class AdsIntegrationTest : public Grpc::GrpcClientIntegrationParamTest, public HttpIntegrationTest {
  