Remove included file string_split.h from payload_signer.cc
This is to remove the direct dependency on libchrome.
Remove unused header base/string/string_split.h.
Bug: 360917504
Test: build
Change-Id: I67db7e9fc58890ebc61b6388bca9196310a789a3
diff --git a/payload_generator/payload_signer.cc b/payload_generator/payload_signer.cc
index 11e136f..4b24eba 100644
--- a/payload_generator/payload_signer.cc
+++ b/payload_generator/payload_signer.cc
@@ -23,7 +23,6 @@
#include <base/logging.h>
#include <base/strings/string_number_conversions.h>
-#include <base/strings/string_split.h>
#include <base/strings/string_util.h>
#include <brillo/data_encoding.h>
#include <openssl/err.h>