Halve the number of threads in OatFileAssistantBaseTest.RaceToGenerate. am: aed0183b0d am: 2bbb0e1319 am: 7600c99448 am: 9bdb67ce1a

Original change: https://android-review.googlesource.com/c/platform/art/+/2117752

Change-Id: Ic9b755ae4ba6d10a121e59229534a1965f6e45b8
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/runtime/oat_file_assistant_test.cc b/runtime/oat_file_assistant_test.cc
index 15182b4..30852fe 100644
--- a/runtime/oat_file_assistant_test.cc
+++ b/runtime/oat_file_assistant_test.cc
@@ -1362,7 +1362,7 @@
   // take a while to generate.
   Copy(GetLibCoreDexFileNames()[0], dex_location);
 
-  const size_t kNumThreads = 32;
+  const size_t kNumThreads = 16;
   Thread* self = Thread::Current();
   ThreadPool thread_pool("Oat file assistant test thread pool", kNumThreads);
   std::vector<std::unique_ptr<RaceGenerateTask>> tasks;