NetEq fuzzer: reduce max input size slightly to avoid timeout

Notry=True

Bug: chromium:988542
Change-Id: I10610f29cd3bb67bf6aa6c40654a2b5a600969e4
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/149170
Commit-Queue: Henrik Lundin <henrik.lundin@webrtc.org>
Reviewed-by: Ivo Creusen <ivoc@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#28898}

test/fuzzers/neteq_signal_fuzzer.cc

@@ -148,7 +148,7 @@ bool MapHas(const std::map<int, T>& m, int key, const T& value) {
 }  // namespace
 
 void FuzzOneInputTest(const uint8_t* data, size_t size) {
-  if (size < 1 || size > 70000) {
+  if (size < 1 || size > 65000) {
     return;
   }