Revert "modem_svc: move shared_modem_platform related sepolicy t..."

Revert submission 30519089-move_modem_sepolicy

Reason for revert: DroidMonitor: Potential culprit for http://b/380274930 - verifying through ABTD before revert submission. This is part of the standard investigation process, and does not mean your CL will be reverted.

Reverted changes: /q/submissionid:30519089-move_modem_sepolicy

Change-Id: I7fc88068835f662d1f1827488089f5898e88ff9d