[libbinder] Disable Sampling PGO for x86, x86_64

Bug: http://b/189438896

Disable sampling PGO (aka AutoFDO) for x86, x86_64.  This is done only
for S (by restricting merge).

Test: verify abi stability across partner and internal builds.

(arbitrary merged-in tag to restrict to sc-dev)

Merged-In: Iba9db702ca6f4a0e590e275bf80e770fb1c7361f
Change-Id: I53b4595c43ade6d068c9c53457cd7e287cec92be