Cleanup NNAPI VTS tests

This CL includes the following cleanups:
* namespace compression
* remove "using" from header files
* remove no-op code, default no-op constructors
* clang-formats the code

Bug: N/A
Test: mma
Test: VtsHalNeuralnetworksV1_*TargetTest
Change-Id: I023997d8686ca65223858eed3a0881f5444ed2d6
Merged-In: I023997d8686ca65223858eed3a0881f5444ed2d6
(cherry picked from commit bbe5dad26674e8fac9570f52814571f626f09a3b)
diff --git a/neuralnetworks/1.2/vts/functional/ValidateModel.cpp b/neuralnetworks/1.2/vts/functional/ValidateModel.cpp
index a3220fa..86afa31 100644
--- a/neuralnetworks/1.2/vts/functional/ValidateModel.cpp
+++ b/neuralnetworks/1.2/vts/functional/ValidateModel.cpp
@@ -21,19 +21,12 @@
 #include "GeneratedTestHarness.h"
 #include "VtsHalNeuralnetworks.h"
 
-namespace android {
-namespace hardware {
-namespace neuralnetworks {
-namespace V1_2 {
+namespace android::hardware::neuralnetworks::V1_2::vts::functional {
 
+using implementation::PreparedModelCallback;
+using V1_0::ErrorStatus;
 using V1_0::OperandLifeTime;
 using V1_1::ExecutionPreference;
-
-namespace vts {
-namespace functional {
-
-using ::android::hardware::neuralnetworks::V1_2::implementation::ExecutionCallback;
-using ::android::hardware::neuralnetworks::V1_2::implementation::PreparedModelCallback;
 using HidlToken = hidl_array<uint8_t, static_cast<uint32_t>(Constant::BYTE_SIZE_OF_CACHE_TOKEN)>;
 
 ///////////////////////// UTILITY FUNCTIONS /////////////////////////
@@ -54,7 +47,6 @@
     SCOPED_TRACE(message + " [prepareModel_1_2]");
 
     sp<PreparedModelCallback> preparedModelCallback = new PreparedModelCallback();
-    ASSERT_NE(nullptr, preparedModelCallback.get());
     Return<ErrorStatus> prepareLaunchStatus =
             device->prepareModel_1_2(model, preference, hidl_vec<hidl_handle>(),
                                      hidl_vec<hidl_handle>(), HidlToken(), preparedModelCallback);
@@ -692,8 +684,9 @@
     for (int32_t preference : invalidExecutionPreferences) {
         const std::string message =
                 "mutateExecutionPreferenceTest: preference " + std::to_string(preference);
-        validate(device, message, model, [](Model*) {},
-                 static_cast<ExecutionPreference>(preference));
+        validate(
+                device, message, model, [](Model*) {},
+                static_cast<ExecutionPreference>(preference));
     }
 }
 
@@ -717,9 +710,4 @@
     mutateExecutionPreferenceTest(device, model);
 }
 
-}  // namespace functional
-}  // namespace vts
-}  // namespace V1_2
-}  // namespace neuralnetworks
-}  // namespace hardware
-}  // namespace android
+}  // namespace android::hardware::neuralnetworks::V1_2::vts::functional