Revert "raise class region size to 32GB for arm64 Android"

This reverts commit b5dd9d1.

Android.bp

@@ -26,7 +26,6 @@ common_cflags = [
  "-DREGION_QUARANTINE_QUEUE_LENGTH=1024",
  "-DREGION_QUARANTINE_SKIP_THRESHOLD=33554432", // 32MiB
  "-DFREE_SLABS_QUARANTINE_RANDOM_LENGTH=32",
- "-DCONFIG_CLASS_REGION_SIZE=34359738368", // 32GiB
  "-DN_ARENA=1",
  "-DCONFIG_STATS=true",
  "-DCONFIG_SELF_INIT=false",
@@ -36,6 +35,14 @@ cc_defaults {
  name: "hardened_malloc_defaults",
  defaults: ["linux_bionic_supported"],
  cflags: common_cflags,
+ arch: {
+ arm64: {
+ cflags: ["-DCONFIG_CLASS_REGION_SIZE=2147483648"] // 2GiB
+ },
+ x86_64: {
+ cflags: ["-DCONFIG_CLASS_REGION_SIZE=34359738368"] // 32GiB
+ },
+ },
  conlyflags: ["-std=c17", "-Wmissing-prototypes"],
  stl: "none",
 }