Added Unit test for onDeckSelected

[Haz3-jolt]

Purpose / Description

Added Unit test to function with @NeedsTest.

Fixes

• Created test for onDeckSelected to address "15448: double-selecting deck does nothing".

Approach

• Unit test completed.

How Has This Been Tested?

• Ran the Unit test multiple times, and ensured it is passing.

Checklist

• You have a descriptive commit message with a short title (first line, max 50 chars).
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code
• UI changes: include screenshots of all affected screens (in particular showing any new or changed strings)
• UI Changes: You have tested your change using the Google Accessibility Scanner

[david-allison]

I'd drop the ContentProvider commit so we can merge the onDeckSelected test

[david-allison]

If makeBackendUsable is removed here, does this test fail?

    override fun onCreate(): Boolean {
        // Initialize content provider on startup.
        Timber.d("CardContentProvider: onCreate")
-        AnkiDroidApp.makeBackendUsable(context!!)
        return true
    }

[Haz3-jolt]

Hey this PR was messed up, will redo