Allow system server to set dynamic ART properties.

This change gives a new type (dalvik_dynamic_config_prop) to some ART
properties such as dalvik.vm.dex2oat-cpu-set and adds a new rule to
allow system server to set them.

Bug: 274530433
Test: Locally added some code to set those properties and saw it being
  successfull.
Change-Id: Ie28602e9039b7647656594ce5c184d29778fa089
diff --git a/microdroid/system/private/dex2oat.te b/microdroid/system/private/dex2oat.te
index bd93f6e..1639640 100644
--- a/microdroid/system/private/dex2oat.te
+++ b/microdroid/system/private/dex2oat.te
@@ -31,7 +31,7 @@
 allow dex2oat apex_info_file:file r_file_perms;
 
 # Allow reading dalvik system properties that may affect compilation
-get_prop(dex2oat, dalvik_config_prop)
+get_prop(dex2oat, dalvik_config_prop_type)
 get_prop(dex2oat, device_config_runtime_native_boot_prop)
 
 # Don't audit because we don't configure the compiler through these