Revert "Define core-current-stubs-for-system-modules-exportable"

Revert submission 3316190-core_system_module_exportable

Reason for revert:DroidMonitor: Potential culprit for http://b/375006938 - 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:3316190-core_system_module_exportable

Change-Id: Ia576b4281a57e1236839429169e1d8db897527f5