Don't count DMRH as admin on non managed users.

Don't treat DMRH as an active admin if the user isn't organization
managed. This will allow uninstalling DMRH package if it isn't
preinstalled and uninstalling updates when it is preinstalled on
unmanaged users. Devices managed by Financed DO are not considered
organization managed.

Starting from U DMRH has the tools to protect itself if necessary,
e.g. via DPM.setUserControlDisabledPackages().

Bug: 360807442
Test: btest a.d.c.DevicePolicyManagementRoleHolderTest
Flag: EXEMPT bugfix
Change-Id: I99d86bbe9e7160db9274a5d6bc4ee325d4010f79