Don't throw errors on sharedUid adjustment.

Given that this is "best effort" anyway, stop short of
aborting installs when ABIs can't be adjusted. Otherwise
it will be impossible to test or upgrade an APP that has
a shared UID and changes ABIs. All apps that use a given
sharedUid are expected to use the same instruction set.

Change-Id: Ia9ffd1eb2df7c6ec9a39b23fc40e58794c013749