Add ScreenCaptureAppContentInteractor

ScreenCaptureAppContentInteractor provides access to currently available
app content for given package names.

Test: atest SystemUITests:com.android.systemui.screencapture.common.domain
BUG: 398757866
Flag: com.android.systemui.new_screen_record_toolbar
Change-Id: Id866b7326c55d0863faa1da1d4c3dca0bc93b45f