Use modern c++ code style for incidentd.

This cl does not contain code logic changes.

Bug: 77333635
Test: manual and incidentd_test
Change-Id: Iea0a402b1051defd45159ca267e6dd705f9ffa49
diff --git a/libs/protoutil/src/ProtoOutputStream.cpp b/libs/protoutil/src/ProtoOutputStream.cpp
index a040bd2..015727a 100644
--- a/libs/protoutil/src/ProtoOutputStream.cpp
+++ b/libs/protoutil/src/ProtoOutputStream.cpp
@@ -173,7 +173,7 @@
 }
 
 bool
-ProtoOutputStream::write(uint64_t fieldId, string val)
+ProtoOutputStream::write(uint64_t fieldId, std::string val)
 {
     if (mCompact) return false;
     const uint32_t id = (uint32_t)fieldId;