graphics: make mapper 2.1 VTS utils more reusable

Move V2_1::vts::Gralloc to android.hardware.graphics.mapper@2.1-vts.

Test: VTS
Change-Id: Iecb7fc3cb90b886ad2d9c23a5cab8aef2da6367f
diff --git a/graphics/mapper/2.1/utils/OWNERS b/graphics/mapper/2.1/utils/OWNERS
new file mode 100644
index 0000000..3aa5fa1
--- /dev/null
+++ b/graphics/mapper/2.1/utils/OWNERS
@@ -0,0 +1,4 @@
+# Graphics team
+jessehall@google.com
+olv@google.com
+stoza@google.com