fix(auth, android): fix a null pointer exception that could occur when removing an event listener

[Lyokone]

Description

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Related Issues

closes #10164

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[rrousselGit]

Some e2e test for this would be neat. But otherwise LGTM

[Lyokone]

Some e2e test for this would be neat. But otherwise LGTM

There are already some e2e tests for this case. I couldn't reproduce this error but it was reported through a crashlytics report.