[vm, service] Fix out-of-bounds access when processing requestHeapSnapshot's arguments.

As detected by the ASAN bots.

Change-Id: Ia10ad883afe886d573f0fa32c2096f9e0ac07083
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/113757
Commit-Queue: Ryan Macnak <rmacnak@google.com>
Reviewed-by: Alexander Markov <alexmarkov@google.com>

https://dart.googlesource.com/sdk/+/f37fdef1c2d1b5e08a64cdc4909091764094c3b7
diff --git a/commits.json b/commits.json
index bc21ae0..a4796e6 100644
--- a/commits.json
+++ b/commits.json
@@ -1,5 +1,5 @@
 {
   "external/github.com/flutter/engine":"99ee3c2b0df7911baa390fa897cefc836605d154",
   "external/github.com/flutter/flutter":"4d81b0c9708f57e545e96f0e6817f5eab3fc68ee",
-  "sdk":"5087b993610ec8125a1f594617e9fa8d64ecc510"
+  "sdk":"f37fdef1c2d1b5e08a64cdc4909091764094c3b7"
 }
\ No newline at end of file