Annotating a class with @SystemApi makes its members @SystemApi

This change fixes a bug that annotating a class in services.jar as
@SystemApi doesn't automatically make its member fields and methods as
@SystemApi. The problem was due to a wrong option to the metalava.

Bug: 147322525
Test: cherry-pick ag/10037363 and `m update-api`.
services/api/current.txt contains all the symbols from the
SystemService class.

Change-Id: I30a515761f8d1792593f207fa4e268ab68a81480