I noticed that after the upgrade to 2.5.1, the app size increased considerably. I did a git bisect run which shows
Author: Ricki Hirner <email@example.com>
Date: Fri Apr 19 01:55:55 2019 +0200
Use Conscrypt; show progress bar when loading account activity
as the offending commit.
App sizes before this commit
After this commit
So, about a 50% in size increase.