Created a SharedMinimal helper.

This class contains the bare minimum shared stuff that can be used without
bloating the APK size of the minimal app that is used on Android TV.

Test: atest CtsAppSecurityHostTestCases:ScopedDirectoryAccessTest
Bug: 72100982

Change-Id: I29deeaeda86fa34d04d2aef2c4d20b34de2c86c1