zenfone6: use our own custom postintall script

Change-Id: I0368db9399d7500b6e3f3055a91d18074d0990be
diff --git a/device.mk b/device.mk
index f11b866..7e34dc1 100755
--- a/device.mk
+++ b/device.mk
@@ -41,10 +41,13 @@
 
 AB_OTA_POSTINSTALL_CONFIG += \
     RUN_POSTINSTALL_system=true \
-    POSTINSTALL_PATH_system=system/bin/otapreopt_script \
+    POSTINSTALL_PATH_system=system/bin/omnipreopt_script \
     FILESYSTEM_TYPE_system=ext4 \
     POSTINSTALL_OPTIONAL_system=true
 
+PRODUCT_PACKAGES += \
+    omnipreopt_script
+
 # ANT+
 PRODUCT_PACKAGES += \
     AntHalService