On userdebug builds we can now profile system server without disabling
selinux. This is the final piece, and allows the system server to save its
own profile.

Test: manual, on a device with system server profiling enabled
Bug: 73313191

(cherry picked from commit 71d8467b)

Change-Id: I93e7e01bfbd3146a8cfd26a1f6e88b640e9c4e0f