Check DELETE_ALL_USERS flag when uninstalling APEX

Currently, uninstalling APEXs checks whether the userId is equal
to UserHandle.USER_ALL, but recent changes mean that this will
never be the case. Instead, pass the uninstall flags to
uninstallApex() and only uninstall if the DELETE_ALL_USERS flag
has been set.

Test: atest RollbackManagerHostTest
Bug: 145341792
Bug: 145313329
Change-Id: Iff02ae6d2aa6de2c824220f0248efb41d6190978