Add a persist.wm.debug property type and associated permissions

This is intended for wm properties related to wmshell/sysui.
Using this context allows sysui to manipulate these properties
in debug builds.

Bug: 219067621
Test: manual
Change-Id: I5808bf92dbba37e9e6da5559f8e0a5fdac016bf3
diff --git a/private/property_contexts b/private/property_contexts
index a15c78f..8477924 100644
--- a/private/property_contexts
+++ b/private/property_contexts
@@ -102,6 +102,7 @@
 sys.lmk.                u:object_r:system_lmk_prop:s0
 sys.trace.              u:object_r:system_trace_prop:s0
 wrap.                   u:object_r:zygote_wrap_prop:s0 prefix string
+persist.wm.debug.       u:object_r:persist_wm_debug_prop:s0
 
 # Suspend service properties
 suspend.max_sleep_time_millis u:object_r:suspend_prop:s0 exact uint