Update otelopscol Submodule

[LujieDuan]

Description

Update otelopscol submodule:

• otelopscol has been upgraded to 0.87.0;
• As part of the otel upgrade, make changes on the agent side for b/308685155, b/308673768 and b/308675258;

Related issue

b/305047490

How has this been tested?

Integration tests.

Checklist:

• Unit tests
  • Unit tests do not apply.
  • Unit tests have been added/modified and passed for this PR.
• Integration tests
  • Integration tests do not apply.
  • Integration tests have been added/modified and passed for this PR.
• Documentation
  • This PR introduces no user visible changes.
  • This PR introduces user visible changes and the corresponding documentation change has been made.
• Minor version bump
  • This PR introduces no new features.
  • This PR introduces new features, and there is a separate PR to bump the minor version since the last release already.
  • This PR bumps the version.

[jefferbrecht]

GoogleCloudPlatform/opentelemetry-operations-collector#189 was just merged, mind repointing to the latest HEAD?

[braydonk]

LGTM