Add Optional match fields support to PI subsystem

Change-Id: Ic458f59cab98340e40c04a0ad060d3c725ac5dbb
diff --git a/protocols/p4runtime/ctl/src/test/resources/test_p4runtime_translation.p4 b/protocols/p4runtime/ctl/src/test/resources/test_p4runtime_translation.p4
index 6ebf306..7f5431c 100644
--- a/protocols/p4runtime/ctl/src/test/resources/test_p4runtime_translation.p4
+++ b/protocols/p4runtime/ctl/src/test/resources/test_p4runtime_translation.p4
@@ -130,7 +130,7 @@
             local_metadata.ingress_port : exact;
             hdr.ethernet.srcAddr        : exact;
             hdr.ethernet.dstAddr        : exact;
-            hdr.ethernet.etherType      : exact;
+            hdr.ethernet.etherType      : optional;
         }
         actions = {
             set_egress_port;