Summary:
This should hopefully unblock our Android builds for real this time. I didn't realise that the AGP itself seems to ship with a version of Dokka, so just removing the import didn't actually address the problem we were seeing.
Pull Request resolved: https://github.com/facebook/flipper/pull/5005
Test Plan:
```
./gradlew publishToMavenLocal -PRELEASE_SIGNING_ENABLED=false
```
This now succeeds.
Reviewed By: jknoxville
Differential Revision: D48312784
Pulled By: passy
fbshipit-source-id: f049e089a511726857f544386fe13dcb50fb2971
29f072fc75