Rotate CUP key to Key 6.

components/update_client/request_sender.cc

Index: components/update_client/request_sender.cc
diff --git a/components/update_client/request_sender.cc b/components/update_client/request_sender.cc
index b2296a21b2f20397b9435a60796175fa30ff6440..45634b50d410cea5f5a752a6898525099ee52432 100644
--- a/components/update_client/request_sender.cc
+++ b/components/update_client/request_sender.cc
@@ -23,10 +23,10 @@ namespace update_client {
 namespace {
 
 // This is an ECDSA prime256v1 named-curve key.
-const int kKeyVersion = 5;
+const int kKeyVersion = 6;
 const char kKeyPubBytesBase64[] =
-    "MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEB+Yi+3SdJKCyFJmm+suW3CyXygvVsbDbPnJgoC"
-    "X4GeTtoL8Q/WjPx7CGtXOL1Xjbx0VPPN3DrvqZSL/oXy9hVw==";
+    "MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAECEDSRcZPKv8k4JEYbF7MJxxx56m+x8Z+svg5gB"
+    "mRX1J8A9DYRL6NvFkNcmcRtSNemUm7/iqrUnxaadkqcWSODw==";
 
 }  // namespace