Support Android 5 (COMMUNITY) (#2955)

* Android 5 support

* Hide background priority settings on Android 5

Since these settings make no sense there, we are hiding them below Android
Marshmellow.

* Use AppCompat Toolbar

This makes the three-dot menu visible on Android 5

* Fix background color of behavior icons on Android 5

* Fix TAN digits for Android 5

This is a very weird way of doing it, but since Android 5 doesn't
support the height attribute, it appears to be the best solution.
Via https://stackoverflow.com/a/19239478

.

* Fix cardTracing style on Android 5

Since this backgroundTint was not applied, simply use the card_dark
drawable that already has the color we want.

* Remove splash screen on API < 23

Splash screens on Android 5 are very broken, as the images on the splash
screen are streched to fit the screen width. Therefore, the splash
screen can only be shown on API >= 23.

* Remove unused import to fix lint

* Fix tests

* Undo change to min sdk version

This partially reverts commit 2edced1c532ff235fd6d09c8cf19a4a10b491d51.

* Small improvements to compat changes

* Change BehaviorInfoRow to use ViewCompat call except if on 5.0

* Improve code readability

* Move restore non-hacky TAN input drawables for Android >= 6

* Fix drawable files that were placed the wrong way round

* Add comments to Android 5 TAN digit assets

As suggested by @vaubaehn

* Remove unused imports

* Use BuildVersionWrap again in NetworkStateProvider

This allows mocking the SDK version in tests

* Update splash screen

* Compat for new code

* Fix typo

* Don't migrate encrypted shared prefs on API < 23

Co-authored-by: harambasicluka <64483219+harambasicluka@users.noreply.github.com>
Co-authored-by: Mohamed <mohamed.metwalli@sap.com>
Co-authored-by: Matthias Urhahn <matthias.urhahn@sap.com>