Define ro.llndk.api_level

ro.llndk.api_level shows the maxium vendor api level that the llndk
in the platform supports.

Bug: 312098788
Test: getprop ro.llndk.api_level
Change-Id: I139524724e458300a3c1430c94595e9fa25a85dd
diff --git a/private/property_contexts b/private/property_contexts
index 6d1c2f6..3055ec0 100644
--- a/private/property_contexts
+++ b/private/property_contexts
@@ -1140,6 +1140,7 @@
 ro.board.first_api_level u:object_r:build_vendor_prop:s0 exact int
 ro.board.api_level       u:object_r:build_vendor_prop:s0 exact int
 ro.board.api_frozen      u:object_r:build_vendor_prop:s0 exact bool
+ro.llndk.api_level       u:object_r:build_vendor_prop:s0 exact int
 ro.vendor.api_level      u:object_r:build_vendor_prop:s0 exact int
 
 # Boot image build props set by /{second_stage_resources/,}boot/etc/build.prop