[ONOS-7143] Add arbitration update support by P4RuntimeClient

Change-Id: I671275576018d50447f969166a7b42a28dd93b1d
diff --git a/protocols/p4runtime/proto/BUCK b/protocols/p4runtime/proto/BUCK
index a50c71f..f8623f8 100644
--- a/protocols/p4runtime/proto/BUCK
+++ b/protocols/p4runtime/proto/BUCK
@@ -5,7 +5,7 @@
 PROTOBUF_VER = '3.0.2'
 GRPC_VER = '1.3.0'
 
-PI_COMMIT = '9fc50cd0a0187eb1346272524d4b8bafb51bb513'
+PI_COMMIT = 'a8814a8ac40838a9df83fe47a17a025b69026fcf'
 PI_BASEURL = 'https://github.com/p4lang/PI.git'
 
 # Wondering which .proto files to build? Check p4runtime's Makefile: