sepolicy: Add context for ro.boot.product.vendor.sku

ro.boot.product.vendor.sku can be set and read in vendor. This
property can be used to differentiate configuration at runtime.

Bug : 148582757
Test: Set this property in vendor and use it for building
      capabilities via SystemConfig.

Change-Id: I4ac29097f26e2f19b90b0d001820bb9144963d21
1 file changed