Add apexd_config_prop type

This type is used for properties that provides per-device configuration
for apexd behaviour (so far - timeouts for creating/deleting dm device).

Test: builds
Bug: 182296338
Change-Id: Ib815f081d3ab94aa8c941ac68b57ebe661acedb9
diff --git a/private/property_contexts b/private/property_contexts
index 98ac9bf..4120b51 100644
--- a/private/property_contexts
+++ b/private/property_contexts
@@ -244,6 +244,8 @@
 persist.device_config.global_settings.sys_traced u:object_r:device_config_sys_traced_prop:s0
 
 apexd.                  u:object_r:apexd_prop:s0
+apexd.config.dm_delete.timeout           u:object_r:apexd_config_prop:s0 exact uint
+apexd.config.dm_create.timeout           u:object_r:apexd_config_prop:s0 exact uint
 persist.apexd.          u:object_r:apexd_prop:s0
 
 bpf.progs_loaded        u:object_r:bpf_progs_loaded_prop:s0