Skip front buffer test if not supported

Bug: 218383959
Test: this
Change-Id: I61beba63556c1d6a32e220fffd8e4b4fdfd8bd94
diff --git a/graphics/allocator/aidl/vts/VtsHalGraphicsAllocatorAidl_TargetTest.cpp b/graphics/allocator/aidl/vts/VtsHalGraphicsAllocatorAidl_TargetTest.cpp
index 346c208..59af5cf 100644
--- a/graphics/allocator/aidl/vts/VtsHalGraphicsAllocatorAidl_TargetTest.cpp
+++ b/graphics/allocator/aidl/vts/VtsHalGraphicsAllocatorAidl_TargetTest.cpp
@@ -277,6 +277,7 @@
     if (!supported) {
         ASSERT_EQ(nullptr, buffer.get())
                 << "Allocation succeeded, but IMapper::isSupported was false";
+        GTEST_SKIP();
     } else {
         ASSERT_NE(nullptr, buffer.get()) << "Allocation failed, but IMapper::isSupported was true";
     }
@@ -318,6 +319,7 @@
     if (!supported) {
         ASSERT_EQ(nullptr, buffer.get())
                 << "Allocation succeeded, but IMapper::isSupported was false";
+        GTEST_SKIP();
     } else {
         ASSERT_NE(nullptr, buffer.get()) << "Allocation failed, but IMapper::isSupported was true";
     }