Dont fall back to installing on sdcard when internal storage is filled up

when the install location is set to internal only. Similary if install
location is set to external only(via adb), dont fall back to installing on
internal storage if sdcard is filled up.
If nothing is specified ie install location is set to let system decide,
we just check on internal storage.
Fix tests

Change-Id: I7400ccc131782d9c45284bd9ebd0dee43a3b412b