* improve error message

* log last error response

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* update secret

* update test case to make sure failure reason is included

* update test

* update secret

---------

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

…1624)

* Adding a flow in impersonated credentials to check if a subject is specificed for domain-wide delegation auth.

* Adding a flow in impersonated credentials to check if a subject is specificed for domain-wide delegation auth.

* Minor fixes to dwd flow in impersonation

* Adding a flow in impersonated credentials to check if a subject is specificed for domain-wide delegation auth.

* deleted repeated

* delete repeated code

* Fixing where source credentials authentication header info is, and target scopes.

* Formatted code to uniform standard

* Fixing lint and coverage failures from kokoro tests

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Co-authored-by: Brian Jung <brianhmj@google.com>
Co-authored-by: arithmetic1728 <58957152+arithmetic1728@users.noreply.github.com>

#1655)

* chore: Add warnings regarding consuming externally sourced credential configurations

* update syntax

* remove in ADC

* period

* make it warning

* update warning syntax

* update secret after rebase

Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>