internal/telemetry: normalize the event reciever names to all use ev
internal/telemetry: normalize the event reciever names to all use ev

Change-Id: Ie622d8d5c4f1c7c272400e549981cd182fe0ab67
Reviewed-on: https://go-review.googlesource.com/c/tools/+/225377
Run-TryBot: Ian Cottrell <52376736e5e84615ec49f9c1843b8acc178b1d8d@google.com>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Robert Findley <9179eee875d1ee628c37fb47d7e749e855ffd21f@google.com>

golang/tools,golang/tools,golang/tools,golang/tools,golang/tools