Remove INSTALLED_USERS extra from ACTION_PACKAGE_ENABLE_ROLLBACK.

This changes RollbackManagerServiceImpl to use the list of installed users
that is passed in to snapshotAndRestoreUserData for the purpose of snapshotting.

With this change, it is no longer necessary for the list of installed users to be
added as an extra to the ENABLE_ROLLBACK intent, so that extra
(EXTRA_ENABLE_ROLLBACK_INSTALLED_USERS) is removed.

Bug: 139181444
Test: atest RollbackTest
Test: atest AppDataRollbackHelperTest
Change-Id: Iffd63977a7498e3cba20d2039af623c921d38f57