Remove ApkAssets access in finalizer

ResourcesProvider#finalize called ApkAssets#close. ApkAssets#close is
called during ApkAssets#finalize. If a ResourcesProvider and its
corresponding ApkAssets are finalized concurrently, there may be a
chance that the ApkAsset could be finalized first and then
ResourcesProvider calls ApkAssets#close on the object that has already
been finalized.

This may not fix the bug, but there is no reason to close the ApkAsset
during finalization of the ResourcesProvider.

Bug: 159041693
Test: none
Change-Id: I317ca982df2e11a18ccd6c95c74565dbac417bd6