Changed selection color for black theme
Changed indicator color to black secondary
Fix indicator flickering when scrolling
Applied patch
Fix unsharp selection icon
Add selection indicators to small and compact view
I kept the classes in the encoding package and turned them into wrappers for
Guava. I also changed the functions in the Base32 class to take and return
strings insteads if character arrays.
Instead of showing the reminder after x unlocks, I decided to show the reminder
2 weeks after the vault was last unlocked with the password. Let me know if you
agree with that.

We noticed after the v1.1 release that we need to switch our external storage
access code over to use the Storage Access Framework. The export functionality
was the only piece of code that still used the deprecated method and this patch
addresses that.
The Storage Access Framework is a little annoying to work with, but I don't
think it'll be too painful for our usecase. This switch comes with some nice
benefits for users as well. Users are now able to select a custom storage
location, which can be local or in the cloud.
This also removes ``requestLegacyExternalStorage`` from the manifest, as we
don't need it anymore.
We decided on calling the state file the "vault" a while back. This patch makes
the naming consistent across the codebase. I left "DatabaseImporter" classes
alone, because I'm not sure what a better name for those would be.
This patch replaces the usage of the deprecated FingerprintManager API with
BiometricPrompt. This uses the Android X library, so we get the native biometric
prompt on recent versions of Android and a Google-made one on older versions. By
not working with custom prompts for biometric authentication like we do now, we
can be sure that any issues like #70, #81, #237 are not actually our fault.
Here's what it looks like:

As a nice aside, this also adds support for the new facial recognition as an
authentication method on Pixel 4 phones.
This is still a draft, but early feedback is welcome.
I think this makes the highlight/reveal functionality feel a bit more
consistent, by not allowing multiple entries to be revealed at the same time,
just like you can't have multiple highlighted entries. Here's video of what it
looks like: https://alexbakker.me/u/3a9dhplrj2.mp4.
This adds an option to highlight tapped entries, so that it's easier to
distinguisch between the one you're trying to enter into a website and the other
ones.
Only one entry can be highlighted at a time. Perhaps it would make sense to
change our tap to reveal functionality to behave the same, so that the two
features are nicely in sync. I can address that in a separate PR if we decide to
do so.
This also fixes an issue with the use of the Iconics library where it was
initialized twice. I also removed the dependency to [AndroidX Preference
eXtended](https://github.com/takisoft/preferencex-android), as there don't seem
to be any issues with using the vanilla AndroidX preference library anymore.