fix(oauth): add client id to token exchange

[davidkl97]

fixes #2806 add client id to token request, adhering to RFC 6749

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[adk-bot]

Response from ADK Triaging Agent

Hello @davidkl97, thank you for creating this PR!

This PR is a bug fix, could you please associate the github issue with this PR? If there is no existing issue, could you please create one?

In addition, could you please provide logs or screenshot after the fix is applied?

This information will help reviewers to review your PR more efficiently. Thanks!

[davidkl97]

Hey @Jacksunwei , can you review this please?

[xuanyang15]

@davidkl97 Thanks for creating this PR! Have you verified it works as expected end to end?

[davidkl97]

Hey @xuanyang15 , yes it works as expected once client id is passed