SF: Fix a sporadic crash during multi-display boot

The Scheduler is created when the first commit adds the primary display,
and accessed whenever a commit adds a physical display. Transactions are
ordered by display token, which is an arbitrary address.

In a multi-display boot, the addition of the primary display could be
reordered after other displays, causing a crash when the Scheduler is
accessed before creation.

As a short-term workaround until Scheduler initialization is decoupled
from commit of display transactions, commit the primary display first.

Bug: 244442572
Test: Boot
Change-Id: I62c4b5299de329a02e60d5f2529ed49907d74415