Address ANAPIC review comments -- hal.

- Document that IPreparedModel::execute*WithConfig are for single-time
  usages, and IPreparedModel::createReusableExecution is for reusable
  usages.
- Make PrepareModelConfig::cacheToken a fixed sized array.

Fixes: 215566186
Test: VtsHalNeuralnetworksTargetTest
Test: NNT_static
Change-Id: I9c5a49c46a3eac2828b9eb666f3d742038493121
diff --git a/neuralnetworks/aidl/vts/functional/Utils.h b/neuralnetworks/aidl/vts/functional/Utils.h
index 4e0a4aa..ccb0778 100644
--- a/neuralnetworks/aidl/vts/functional/Utils.h
+++ b/neuralnetworks/aidl/vts/functional/Utils.h
@@ -21,6 +21,7 @@
 #include <gtest/gtest.h>
 
 #include <algorithm>
+#include <array>
 #include <iosfwd>
 #include <string>
 #include <utility>
@@ -47,6 +48,7 @@
 inline constexpr int64_t kOmittedTimeoutDuration = -1;
 inline constexpr int64_t kNoDuration = -1;
 inline const std::vector<uint8_t> kEmptyCacheToken(IDevice::BYTE_SIZE_OF_CACHE_TOKEN);
+inline const std::array<uint8_t, IDevice::BYTE_SIZE_OF_CACHE_TOKEN> kEmptyCacheTokenArray{};
 
 // Returns the amount of space needed to store a value of the specified type.
 //
diff --git a/neuralnetworks/aidl/vts/functional/ValidateModel.cpp b/neuralnetworks/aidl/vts/functional/ValidateModel.cpp
index 931ba25..060434e 100644
--- a/neuralnetworks/aidl/vts/functional/ValidateModel.cpp
+++ b/neuralnetworks/aidl/vts/functional/ValidateModel.cpp
@@ -85,7 +85,7 @@
     std::shared_ptr<PreparedModelCallback> preparedModelCallback =
             ndk::SharedRefBase::make<PreparedModelCallback>();
     const auto prepareLaunchStatus = device->prepareModelWithConfig(
-            model, {preference, priority, kNoDeadline, {}, {}, kEmptyCacheToken, {}, {}},
+            model, {preference, priority, kNoDeadline, {}, {}, kEmptyCacheTokenArray, {}, {}},
             preparedModelCallback);
     ASSERT_FALSE(prepareLaunchStatus.isOk());
     ASSERT_EQ(prepareLaunchStatus.getExceptionCode(), EX_SERVICE_SPECIFIC);
diff --git a/neuralnetworks/aidl/vts/functional/VtsHalNeuralnetworks.cpp b/neuralnetworks/aidl/vts/functional/VtsHalNeuralnetworks.cpp
index 51b4805..bf87f15 100644
--- a/neuralnetworks/aidl/vts/functional/VtsHalNeuralnetworks.cpp
+++ b/neuralnetworks/aidl/vts/functional/VtsHalNeuralnetworks.cpp
@@ -72,7 +72,7 @@
                                                 kNoDeadline,
                                                 {},
                                                 {},
-                                                kEmptyCacheToken,
+                                                kEmptyCacheTokenArray,
                                                 {},
                                                 {}},
                                                preparedModelCallback);