We recently added the Android NDK to our Android images (see, for example, https://github.com/CircleCI-Public/circleci-dockerfiles/blob/master/android/images/api-28-alpha/Dockerfile#L151).
In order to keep the overall size of these images down (currently at nearly 3GB including the NDK), we will be moving the NDK into a specific, ndk-tagged variant, which you will be able to find here:
https://hub.docker.com/r/circleci/android/tags
For a preview of the new tagging structure, see the images in our staging environment:
https://hub.docker.com/r/ccistaging/android/tags
The existing variants will stay the same, except that they will no longer contain the NDK.
These changes will take place by Friday, August 31st. To avoid any changes to the image you’re currently using, please lock your configurations to the sha256 of your current image before that date. (However, if you are using the NDK, you can always switch your config to use the new, ndk-tagged variant after that date.)
For more details on how to use an image by SHA, please see our documentation:
https://circleci.com/docs/2.0/executor-types/#public-convenience-images-on-docker-hub