Throw IOException when checking if invalid target defines overlayable

PackageInfo can be null for cases where the target is missing, and
this should not crash in those cases. Mirrors the behavior of
getOverlayableForTarget by converting null to an IOException.

Bug: 147255897

Change-Id: I345dc68b7e6bea65f3f5da7a49a9136e07ba3793
1 file changed