Update the cronet-bot config to send email alerts to oncall directly and cronet-sheriff+bot.

Change-Id: I1127d2bceaa5fa0fcb596f1f5b854e8e75572080
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1641964Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: John Budorick <jbudorick@chromium.org>
Auto-Submit: Zhongyi Shi <zhongyi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#665717}

infra/config/luci-notify.cfg

@@ -203,7 +203,9 @@ notifiers {
   notifications {
     on_change: true
     email {
-      recipients: "cronet-sheriff@google.com"
+      recipients: "cronet-sheriff-oncall1@google.com"
+      recipients: "cronet-sheriff-oncall2@google.com
+      recipients: "cronet-sheriff+bot@google.com"
     }
   }
   builders {