Add Optional match fields support to PI subsystem

Change-Id: Ic458f59cab98340e40c04a0ad060d3c725ac5dbb
diff --git a/protocols/p4runtime/ctl/src/test/resources/test_p4runtime_translation_p4info.txt b/protocols/p4runtime/ctl/src/test/resources/test_p4runtime_translation_p4info.txt
index 241d989..b984b4c 100644
--- a/protocols/p4runtime/ctl/src/test/resources/test_p4runtime_translation_p4info.txt
+++ b/protocols/p4runtime/ctl/src/test/resources/test_p4runtime_translation_p4info.txt
@@ -36,7 +36,7 @@
     id: 4
     name: "hdr.ethernet.etherType"
     bitwidth: 16
-    match_type: EXACT
+    match_type: OPTIONAL
   }
   action_refs {
     id: 27607748