change in behaviour for otlp grpc exporter

[codeboten]

Describe the bug
The following change causes the default for the grpc exporter transport to change from secure to insecure. ebb0fbd#diff-2eb38d27ab53ca22abef502c1b39e68f28165a4eb3aa92e2c1d2314ab8991a59R194-R199

I reproduced the change in behaviour by using the same configuration both before and after this change.
This was the config:

exporters:
  logging:
      loglevel: debug
  otlp:
    endpoint: ingest.lightstep.com:443
    headers:
        "lightstep-access-token": "redacted"

The fix was to set the following options:

exporters:
  logging:
      loglevel: debug
  otlp:
    endpoint: ingest.lightstep.com:443
    headers:
        "lightstep-access-token": "redacted"
    tls:
      insecure: false

Two things I'm looking for with this issue:

1. ensure the change in behaviour was intentional
2. if so, ensure we have this documented in the changelog/release notes

[jpkrohling]

This should not have happened and should be reverted. Making the connection secure by default was a conscious decision and it should remain like that.

[codeboten]

As discussed at the Oct 13 SIG meeting, this behaviour was unexpected. Will add a PR to reverse the behaviour.