NNAPI VTS: use max time point instead of uint64_t max

Bug: 149441015
Test: mma
Test: VtsHalNeuralnetworksV1_3TargetTest
Change-Id: Ic74f83242cbe04a4cec47adbfc51002fdf8bb47d
diff --git a/neuralnetworks/1.3/vts/functional/QualityOfServiceTests.cpp b/neuralnetworks/1.3/vts/functional/QualityOfServiceTests.cpp
index 2f1e05c..76d133a 100644
--- a/neuralnetworks/1.3/vts/functional/QualityOfServiceTests.cpp
+++ b/neuralnetworks/1.3/vts/functional/QualityOfServiceTests.cpp
@@ -67,8 +67,10 @@
             deadline.nanosecondsSinceEpoch(nanosecondsSinceEpoch);
         } break;
         case DeadlineBoundType::UNLIMITED: {
-            uint64_t unlimited = std::numeric_limits<uint64_t>::max();
-            deadline.nanosecondsSinceEpoch(unlimited);
+            const auto maxTime = std::chrono::time_point<std::chrono::steady_clock,
+                                                         std::chrono::nanoseconds>::max();
+            const uint64_t nanosecondsSinceEpoch = maxTime.time_since_epoch().count();
+            deadline.nanosecondsSinceEpoch(nanosecondsSinceEpoch);
         } break;
     }
     return deadline;