Revert "Revert "[res] Don't create extra asset provider when not..."

Revert submission 31216694-revert-31021037-TXGRFMNZKV

Reason for revert: relanding with a fix
The fix is to still return a null AssetsProvider when failing
to open the supplied apk, instead of ending up with an
empty provider that will fail later

Reverted changes: /q/submissionid:31216694-revert-31021037-TXGRFMNZKV

Change-Id: Ia8e2cdaddf81683cd58547942d1da3c5df93b087