Allow codepath changes for new OTA packages

When an OTA contains a new package, the system performs some gymnastics
to ensure that we use the most up-to-date version of the package in
either the system image or user directory. But, during boot, we enforce
a package's codepath will never change. This prevents a user-installed
package from ever overriding the system provide package [regardless of
version]. In this one, specific instance, we allow a package's codepath
to change.

Bug: 22179337
Change-Id: I2c29a87801fb5960ffbd2268231446895ad1868f