Add tests with a permanently enabled flag in art-flags.aconfig.

Test: art/test/testrunner/testrunner.py --host 2279-aconfig-flags
Test: art/test/testrunner/testrunner.py --target 2279-aconfig-flags
Test: art/tools/run-gtests.sh \
        /apex/com.android.art/bin/art/x86/art_libartbase_tests \
        | grep Aconfig
Test: m test-art-host-gtest-art_libartbase_tests | grep Aconfig
Bug: 352723620
Change-Id: I693cbef25a8b62f437e6eef95003944f35354177

libartbase/Android.bp

diff --git a/libartbase/Android.bp b/libartbase/Android.bp
index d608272..91c9c5b 100644
--- a/libartbase/Android.bp
+++ b/libartbase/Android.bp
@@ -337,6 +337,7 @@
     ],
     srcs: [
         "arch/instruction_set_test.cc",
+        "base/aconfig_flags_test.cc",
         "base/arena_allocator_test.cc",
         "base/bit_field_test.cc",
         "base/bit_memory_region_test.cc",
@@ -356,10 +357,10 @@
         "base/intrusive_forward_list_test.cc",
         "base/leb128_test.cc",
         "base/logging_test.cc",
-        "base/memfd_test.cc",
-        "base/membarrier_test.cc",
-        "base/memory_region_test.cc",
         "base/mem_map_test.cc",
+        "base/membarrier_test.cc",
+        "base/memfd_test.cc",
+        "base/memory_region_test.cc",
         "base/metrics/metrics_test.cc",
         "base/scoped_flock_test.cc",
         "base/time_utils_test.cc",

libartbase/base/aconfig_flags_test.cc

diff --git a/libartbase/base/aconfig_flags_test.cc b/libartbase/base/aconfig_flags_test.cc
new file mode 100644
index 0000000..8d87325
--- /dev/null
+++ b/libartbase/base/aconfig_flags_test.cc
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "com_android_art_flags.h"
+#include "gtest/gtest.h"
+
+namespace art {
+
+static_assert(COM_ANDROID_ART_FLAGS_TEST == true);
+
+TEST(AconfigFlagsTest, TestFlag) { EXPECT_TRUE(com::android::art::flags::test()); }
+
+}  // namespace art

test/2279-aconfig-flags/src/Main.java

diff --git a/test/2279-aconfig-flags/src/Main.java b/test/2279-aconfig-flags/src/Main.java
index 4a282db..6d600b8 100644
--- a/test/2279-aconfig-flags/src/Main.java
+++ b/test/2279-aconfig-flags/src/Main.java
@@ -14,19 +14,28 @@
  * limitations under the License.
  */
 
-import com.android.libcore.Flags;
-
 public class Main {
     public static void main(String[] args) {
+        // Test a flag in libcore/libcore.aconfig.
         if (!isVTrunkStableFlagEnabled()) {
             throw new AssertionError(
                     "The value of com.android.libcore.v_apis flag is expected to be true.");
         }
+
+        // Test a flag in art/build/flags/art-flags.aconfig.
+        if (!isArtTestFlagEnabled()) {
+            throw new AssertionError(
+                    "The value of com.android.art.flags.test flag is expected to be true.");
+        }
     }
 
     private static boolean isVTrunkStableFlagEnabled() {
         // The Flags class definition is expected to be in core-libart.jar.
-        return Flags.vApis();
+        return com.android.libcore.Flags.vApis();
     }
 
+    private static boolean isArtTestFlagEnabled() {
+        // The Flags class definition is expected to be in core-libart.jar.
+        return com.android.art.flags.Flags.test();
+    }
 }