Switched langchain llm callbacks to use genai utils handler (#3889)

* Removed telemetry from inference callbacks and added calls to genai utils apis instead.

* Fixed errors

* Fixed typecheck errors

* Fixed typecheck errors

* Fixed precommit errors

* added util dependancy

* updated invocation manager

* removed unnecessary dependancies

* fixed precommit

* fixed typecheck

* fixed precommit

* fixed test

* removed unnecessary line

* addressed comments

* fixed errors

* fixed precommit

* removed get_property_value method

* fixed format

* Make tox -e typecheck install langchain, and fixed some of the type
errors. The remaining ones seem like real issues that need to be fixed.

* Please fix reportPossiblyUnboundVariable

* fixed typecheck

* added and updated tests

* Fixed conflicts and removed unnecessary changes

* Fixed precommit

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Co-authored-by: aaronabbott <aaronabbott@google.com>