Add START_TASKS_FROM_RECENTS to @SystemApi

The permission is privileged, so it was already accessible to
non-framework apps. Some methods that require it (such as
ActivityOptions.setLaunchTaskId) are @SystemApi, and it is used in the
Permissions Mainline Module, so the permission constant needs to be
@SystemApi.

Fixes: 242905922
Test: Build
Change-Id: I6105e9b5a7913c14c8824dfda230b753c4e67bf5