[CDM] Check if it's system UID for hidden Perm Sync APIs

Bug: 371975420
Test: Manual test
Flag: EXEMPT bugfix
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:7e5e47611d6f3271df264bb8ca9545ca3ba80361)
Merged-In: I9771ce38728d40b026d94cb6785d55f144c66790
Change-Id: I9771ce38728d40b026d94cb6785d55f144c66790