Update VTS tag version to v8.1_R6

Test:mma
Bug:110561052
Change-Id: I75497ab359c5ba876cfaffb0ef40b19555cc0ea0
diff --git a/tools/vts-tradefed/Android.mk b/tools/vts-tradefed/Android.mk
index 6f3de11..13df254 100644
--- a/tools/vts-tradefed/Android.mk
+++ b/tools/vts-tradefed/Android.mk
@@ -24,7 +24,7 @@
 LOCAL_SUITE_TARGET_ARCH := $(TARGET_ARCH)
 LOCAL_SUITE_NAME := VTS
 LOCAL_SUITE_FULLNAME := "Vendor Test Suite"
-LOCAL_SUITE_VERSION := 8.1_R5
+LOCAL_SUITE_VERSION := 8.1_R6
 LOCAL_STATIC_JAVA_LIBRARIES := \
     libvts_protos_host \