[Composer-VTS] Test to verify MRR and ARR modes are mutually exclusive

Test: atest PerInstance/GraphicsComposerAidlV3Test#GetDisplayConfigurations/0_android_hardware_graphics_composer3_IComposer_default
BUG: 380089524
Flag: EXEMPT test fix
Change-Id: Ib8eb50b1c9f9806ddccded163bc90cfd85747707
diff --git a/graphics/composer/aidl/vts/VtsHalGraphicsComposer3_TargetTest.cpp b/graphics/composer/aidl/vts/VtsHalGraphicsComposer3_TargetTest.cpp
index 8006523..4c8a68e 100644
--- a/graphics/composer/aidl/vts/VtsHalGraphicsComposer3_TargetTest.cpp
+++ b/graphics/composer/aidl/vts/VtsHalGraphicsComposer3_TargetTest.cpp
@@ -1265,6 +1265,16 @@
         EXPECT_TRUE(status.isOk());
         EXPECT_FALSE(displayConfigurations.empty());
 
+        const bool areAllModesARR =
+                std::all_of(displayConfigurations.cbegin(), displayConfigurations.cend(),
+                            [](const auto& config) { return config.vrrConfig.has_value(); });
+
+        const bool areAllModesMRR =
+                std::all_of(displayConfigurations.cbegin(), displayConfigurations.cend(),
+                            [](const auto& config) { return !config.vrrConfig.has_value(); });
+
+        EXPECT_TRUE(areAllModesARR || areAllModesMRR) << "Mixing MRR and ARR modes is not allowed";
+
         for (const auto& displayConfig : displayConfigurations) {
             EXPECT_NE(-1, displayConfig.width);
             EXPECT_NE(-1, displayConfig.height);