Expand uninstallForAll to Admins

Currently, user 0 can uninstall other users' apps. It really has that
ability by virtue of it being an Admin user. But non-user-0 Admins don't
currently have this ability, so we expand that here. This also allows
this ability on HSUM, where human Admin users aren't user 0.

Bug: 384514936
Test: manual confirmation that overflow appears on HSUM device
Test: atest SettingsSpaUnitTests:com.android.settings.spa.app.appinfo.AppInfoSettingsMoreOptionsTest
Flag: EXEMPT bugfix
Change-Id: I976bb63ecced3c128f8109c63c85067f4a0cdf9b