Allow system server uid to bypass location restriction

Blocking system server from giving itself location restriction doesn't
make much sense.

Test: Disable, reboot, observe bootloop, apply patch, build, flash,
          observe successful boot
Bug: 230861324
Bug: 231496105
Merged-In: Ic869da4847e4f39896861f3bf6e83f6f6c76ea62
Change-Id: Ic869da4847e4f39896861f3bf6e83f6f6c76ea62
(cherry picked from commit 1dddfe1f)
Merged-In: Ic869da4847e4f39896861f3bf6e83f6f6c76ea62