I can confirm that the fix proposed in the linked issue (in my previous comment) does work.
As mentioned here: gradle-ndk-strip-debug-symbol-not-applied-bug/app/build.gradle at main · h6ah4i/gradle-ndk-strip-debug-symbol-not-applied-bug · GitHub, I included a configuration like this:
android {
...
ndkVersion = "25.2.9519653"
...
}
It bought down the apk size back down to around 100MB. Will test to see if the couchbase lite database size on disk gets reduced or not.