Revert "Remove a check for AIDs in the OEM range."

We now have a proper mechanism for OEMs to create new AIDs via
config.fs and /vendor/etc/{passwd,group}.  This means that there is no
reason for OEMs to add AIDs by modifying android_filesystem_config.h,
and therefore we can add this check back.

Bug: 27999086
Test: pwd and grp tests pass with custom AIDs in config.fs

This reverts commit a14485ad.

Change-Id: I74a28ff267a595e83cf692b27fd8b5170a021f54