Update WebRTC code version (2022-04-20T04:02:12).

Bug: None
Change-Id: I07b92d60728c72c456646a52e420d589f828f22f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/259459
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@{#36577}
diff --git a/call/version.cc b/call/version.cc
index 23cffc3..82f682c 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 2022-04-19T04:02:48";
+const char* const kSourceTimestamp = "WebRTC source stamp 2022-04-20T04:02:12";
 
 void LoadWebRTCVersionInRegister() {
   // Using volatile to instruct the compiler to not optimize `p` away even