add configuration for self-init

This needs to be disabled for compatibility with the exploit protection
compatibility mode on GrapheneOS. hardened_malloc shouldn't be trying to
initialize itself when exploit protection compatibility mode is enabled.
This has to be handled in our Bionic integration instead.

Android.bp

@@ -29,6 +29,7 @@ common_cflags = [
     "-DCONFIG_CLASS_REGION_SIZE=34359738368", // 32GiB
     "-DN_ARENA=1",
     "-DCONFIG_STATS=true",
+    "-DCONFIG_SELF_INIT=false",
 ]
 
 cc_defaults {