android electrum updates automatically. you don't download android electrum from electrum.org. instead you install it using the playstore.
I also use Electrum on android, and it does not update automatically on my device, maybe it is due to different settings on our devices,
Google Playstore's default setting is to auto-update apps if the device is connected to WiFi.It's accessible in "Playstore's Setting->expand: Network Preferences->Auto-update apps"
So Electrum will automatically update if that setting isn't disabled and if Electrum is installed from the Playstore.
Otherwise, it wont.
Yes, the android binaries downloaded from the electrum.org wont update automatically either.
(might result with "couldn't update" if Playstore tries to update it to a different variant, it may update if similar but I don't want to try)
In OP's case, it's normal for users to accidentally click "Update all" when checking for updates in PlayStore.
Or he just fat-fingered "Update" button.
We're slightly off-topic though since the main issue isn't the cause of his "accidental update".
And he didn't answer any of the questions.
