The current implementation uses MANAGE_USERS, CREATE_USERS, or
QUERY_USERS to check if the user is an admin. However,
QUERY_USERS is not a privileged permission until Android U.
This can cause issues on devices running older Android versions
(e.g., T) where the tethering module requires this check but
doesn't have the necessary permission, leading to crashes.
This change updates the code to use MANAGE_USERS, a privileged
permission since 2015, to reliably determine if the user is
an admin across different Android versions.
Test: Manual on T device:
1. Mock entitlement and enable hotspot
2. Check granted permissions of android.uid.networkstack
Fix: 366816004
Change-Id: Iee060f0225d23c62d836f0211c63b649e539f77b
f014ae2f2a