Add HIDL_FETCH_IScheduleTest declaration

Fix the bug that makes the registerAsServer fail.
sp<IScheduleTest> server =
	IScheduleTest::getService(serviceName, true);
status_t status = server->registerAsService(serviceName);

Bug:38099333
Test: oc-dev on pixel sailfish with a vts test case
  "libhwbinder_latency -i 1"
Change-Id: I892835a25ef7df56a6424da41c0fc477b3a532d8