bigtable: Simulate latency/errors in Bigtable emulator for performance / DiRT testing

[AdamBSteele]

Is your feature request related to a problem? Please describe. I want to use the Cloud Bigtable emulator to test my application's behavior when my Bigtable instance is returning high latency or error rates.

Describe the solution you'd like Add new settings to the Bigtable emulator for inject latency / errors into grpc calls.

Describe alternatives you've considered N/A

Additional context N/A

[telpirion]

Performance tests will be addressed by the Cloud Bigtable clients test project.

[bhshkh]

Cloud Bigtable clients test project addressed conformance testing and not performance tests.