[mdatagen] Undefined packages for generated logs tests

[rogercoll]

Component(s)

cmd/mdatagen

What happened?

Describe the bug
The testing generated files for logs do not include some used packages in the imports section:

Error: internal/metadata/generated_logs_test.go:43:47: undefined: time
Error: internal/metadata/generated_logs_test.go:48:9: undefined: plog
Error: internal/metadata/generated_logs_test.go:49:48: undefined: time (typecheck)

Version: v0.124.0

Steps to reproduce
Receiver that supports logs signal type + go generate ./... + go test

What did you expect to see?

No error

What did you see instead?

Undefined packages

Collector version

v0.124.0

Environment information

Environment

OS: (e.g., "Ubuntu 20.04")
Compiler(if manually compiled): (e.g., "go 14.2")

OpenTelemetry Collector configuration

Log output

Additional context

No response

[github-actions]

Pinging code owners:

• cmd/mdatagen: @dmitryax

See Adding Labels via Comments if you do not have permissions to add labels yourself.

[rogercoll]

fixed with #12908