Let Cloud Run Job use `StructuredLogHandler` instead of `ClougLoggingHandler`

[xSAVIKx]

Is your feature request related to a problem? Please describe.
When using Client.get_default_handler CloudLoggingHandler is being used automatically for Cloud Run jobs resource. And while googleapis/python-logging#877 fixes the missing labels we're still gonna be using background transport when simplier stdout is doing just fine.

Describe the solution you'd like
If we modify this check https://github.com/googleapis/python-logging/blob/62641075042a3da9bb9c059d963bad14a1586b1c/google/cloud/logging_v2/client.py#L388 and allow _RUN_RESOURCE_TYPE OR _CLOUD_RUN_JOB_RESOURCE_TYPE resource type then a structured log handler is gonna be used automatically which should be a better default.

Describe alternatives you've considered
Meanwhile I am using handler = StructuredLogHandler(project_id=client.project) instead of handler = client.get_default_handler() where client is client = CloudLoggingClient()

[parthea]

Transferring to google-cloud-python as the code for python-logging will be migrated there in 1-3 weeks.