Remove PathForOutput from InstallPathToOnDevicePath

The next patches will make more InstallPaths use the Make output
directory, which is not inside PathForOutput.  Fix the assumption
that the InstallPath is relative to PathForOutput by storing
enough information in the InstallPath to find the on-device path
without PathForOutput.

Bug: 204136549
Test: soong tests
Change-Id: Icb3eeef3f1c72f773f333267f8a7dfc503feacb5