Double debug monitor pool size again

aosp/1978988 wasn't quite enough.

Bug: 217607468
Test: Build boot AOSP, Treehugger
Change-Id: Ic6707ac79af1288784e06a0bb88457a9c6a5224c
diff --git a/runtime/monitor_pool.h b/runtime/monitor_pool.h
index 24390f3..e07aa97 100644
--- a/runtime/monitor_pool.h
+++ b/runtime/monitor_pool.h
@@ -200,7 +200,7 @@
   // should be large enough that we don't run out. We run out of address bits if it's > 512.
   // Currently we set it a bit smaller, to save half a page per process.  We make it tiny in
   // debug builds to catch growth errors. The only value we really expect to tune.
-  static constexpr size_t kInitialChunkStorage = kIsDebugBuild ? 4U : 256U;
+  static constexpr size_t kInitialChunkStorage = kIsDebugBuild ? 8U : 256U;
   static_assert(IsPowerOfTwo(kInitialChunkStorage), "kInitialChunkStorage must be power of 2");
   // The number of lists, each containing pointers to storage chunks.
   static constexpr size_t kMaxChunkLists = 8;  //  Dictated by 3 bit index. Don't increase above 8.