Duplicate packages should fail to install

Fail a staged session if there are duplicate packages in apk and
apk-in-apex.

This CL prevents the issue in b/150940087#comment1.

Bug: 150940087
Fix: 161569960
Test: atest StagedInstallInternalTest#testDuplicateApkInApexShouldFail
Change-Id: I4d5f4ba91f41ea2c4a013fee82fa7167e46229f0