Revert "Make setTestMode() a module API"

This reverts commit f272aff2656214ca6a550377f03cd9d913d5037c.

Reason for revert: b/401021983  Despite assurances to the contrary, flagging an existing API for mainline modules makes it unavailable to CTS.

Change-Id: I61f4d938549efd5c6cbd63db45dcf8a6010d5d30
5 files changed