Update WebRTC code version (2023-09-18T04:12:27).

Bug: None
Change-Id: Iab2ec2612399b368817b9b02fd6f217b8509a907
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/320543
Bot-Commit: webrtc-version-updater@webrtc-ci.iam.gserviceaccount.com <webrtc-version-updater@webrtc-ci.iam.gserviceaccount.com>
Commit-Queue: webrtc-version-updater@webrtc-ci.iam.gserviceaccount.com <webrtc-version-updater@webrtc-ci.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#40759}
diff --git a/call/version.cc b/call/version.cc
index fd0bd8a..b56de9a 100644
--- a/call/version.cc
+++ b/call/version.cc
@@ -13,7 +13,7 @@
 namespace webrtc {
 
 // The timestamp is always in UTC.
-const char* const kSourceTimestamp = "WebRTC source stamp 2023-09-17T04:13:24";
+const char* const kSourceTimestamp = "WebRTC source stamp 2023-09-18T04:12:27";
 
 void LoadWebRTCVersionInRegister() {
   // Using volatile to instruct the compiler to not optimize `p` away even