Disable package verifier for staged installs.

This is a temporary measure to allow staged installs for APKs to work on
dev-signed devices.

Test: adb install --staged file.apk on taimen-eng target; adb
install-multi-package file1.apex file2.apex file3.apk file4.apk
Bug: 123753157
Change-Id: I537afbb08cb0a5db37bb823f4b084691dcd2f5d1