authorization_set.cpp: relax serialization of unknown tags

Bug: 119414176
Change-Id: I16722f2a2b1a00a352322c603d2bf18a996d6ee7
(cherry picked from commit 28a6b79f4b15d60d81984b1ea99a3240bb029530)
diff --git a/keymaster/4.0/support/authorization_set.cpp b/keymaster/4.0/support/authorization_set.cpp
index 10d272a..b6cba61 100644
--- a/keymaster/4.0/support/authorization_set.cpp
+++ b/keymaster/4.0/support/authorization_set.cpp
@@ -261,9 +261,8 @@
 template <>
 struct choose_serializer<> {
     static OutStreams& serialize(OutStreams& out, const KeyParameter& param) {
-        LOG(FATAL) << "Trying to serialize unknown tag " << unsigned(param.tag)
+        LOG(ERROR) << "Trying to serialize unknown tag " << unsigned(param.tag)
                    << ". Did you forget to add it to all_tags_t?";
-        abort();
         return out;
     }
 };