Add support for greylist-max-r signatures.

Bug: 156307884
Test: m
Change-Id: I838e348af7c0ca1b3933a8a6e012cddfa6c209aa
diff --git a/libartbase/base/sdk_version.h b/libartbase/base/sdk_version.h
index 219ac86..4a253d2 100644
--- a/libartbase/base/sdk_version.h
+++ b/libartbase/base/sdk_version.h
@@ -34,6 +34,7 @@
   kO_MR1 = 27u,
   kP     = 28u,
   kQ     = 29u,
+  kR     = 30u,
   kMax   = std::numeric_limits<uint32_t>::max(),
 };