Check for caching of sensitive information (Android)

[rachelhamlin]

Problem

Another potential issue spotted by Trail of Bits:

Make sure that you aren't caching anything that should be secure. In the very quick look I took, I didn't see anything such conditions but I wouldn't be surprised if it existed.

Implementation

Please investigate whether this is the case.

Acceptance Criteria

Write-up on whether we are caching any sensitive data on Android. If so, please create a follow-up issue.