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/vts/functional/Android.bp b/graphics/mapper/2.1/vts/functional/Android.bp
index 74d6fa8..ac67af8 100644
--- a/graphics/mapper/2.1/vts/functional/Android.bp
+++ b/graphics/mapper/2.1/vts/functional/Android.bp
@@ -24,5 +24,6 @@
         "android.hardware.graphics.mapper@2.0",
         "android.hardware.graphics.mapper@2.1",
         "android.hardware.graphics.mapper@2.0-vts",
+        "android.hardware.graphics.mapper@2.1-vts",
     ],
 }