Investigate the need to support database downgrading

[grzesiek2010]

Problem description

Our databases (forms, instances, savepoints, entities) currently support downgrading through the #onDowngrade method, which simply recreates the database from scratch. However, this feature may be unnecessary since Android does not allow app downgrades (you must uninstall the newer version before installing an older one).

We began considering this issue in this discussion, so it would be worthwhile to investigate whether we can eliminate the downgrading mechanism entirely or if it is still necessary (for example, if downgrading is possible using ADB or other methods).