Add secontext for ro.product.ab_ota_partitions

Bug: 162148770
Test: build
Change-Id: Iff509cb573462718b876db02f88a3d4a21667267
diff --git a/private/property_contexts b/private/property_contexts
index 357a56c..8f663d0 100644
--- a/private/property_contexts
+++ b/private/property_contexts
@@ -236,6 +236,7 @@
 ro.virtual_ab.enabled   u:object_r:virtual_ab_prop:s0
 ro.virtual_ab.retrofit  u:object_r:virtual_ab_prop:s0
 
+ro.product.ab_ota_partitions u:object_r:ota_prop:s0 exact string
 # Property to set/clear the warm reset flag after an OTA update.
 ota.warm_reset  u:object_r:ota_prop:s0