Add InitGoogleTest to ExchangeFuzzer (#8612)

Summary:
Pull Request resolved: facebookincubator/velox#8612

We call InitGoogleTest in our fuzzer tests so they can be invoked like GTests, including all the flags, even though they're not.

It looks like ExchangeFuzzer is missing this call, so it fails when invoked like a GTest when built in Release mode.

Reviewed By: kagamiori

Differential Revision: D53250534

fbshipit-source-id: e95f5557d081c268470e8268c1d9fe2fada44b3b

velox/exec/tests/ExchangeFuzzer.cpp

@@ -404,6 +404,7 @@ class ExchangeFuzzer : public VectorTestBase {
 int32_t ExchangeFuzzer::iteration_;
 
 int main(int argc, char** argv) {
+  ::testing::InitGoogleTest(&argc, argv);
   folly::Init init{&argc, &argv};
   memory::MemoryManagerOptions options;
   options.useMmapAllocator = true;