Allow for failure in allocation for MapperVts

Bug: 155942443
Test: build, boot
Change-Id: I8698e4cf117d54a6d2ff128cc2e503308188c7e6
diff --git a/graphics/mapper/4.0/utils/vts/MapperVts.cpp b/graphics/mapper/4.0/utils/vts/MapperVts.cpp
index cb90fa0..9f907e6 100644
--- a/graphics/mapper/4.0/utils/vts/MapperVts.cpp
+++ b/graphics/mapper/4.0/utils/vts/MapperVts.cpp
@@ -90,6 +90,9 @@
     mAllocator->allocate(
             descriptor, count,
             [&](const auto& tmpError, const auto& tmpStride, const auto& tmpBuffers) {
+                if (allowFailure && tmpError == Error::UNSUPPORTED) {
+                    return;
+                }
                 ASSERT_EQ(Error::NONE, tmpError) << "failed to allocate buffers";
                 ASSERT_EQ(count, tmpBuffers.size()) << "invalid buffer array";