Make bionic_malloc.h a platform header.

Instead of having platform directories directly include the
private header, create a platform header directory and export it.

Bug: 130763340

Test: Builds.
Change-Id: Ie0f092b3fe077a3de8b90266c0b28bfbc20d0dfa
diff --git a/libc/malloc_hooks/Android.bp b/libc/malloc_hooks/Android.bp
index d119f89..a0f8102 100644
--- a/libc/malloc_hooks/Android.bp
+++ b/libc/malloc_hooks/Android.bp
@@ -49,7 +49,13 @@
     shared_libs: ["libbase"],
 
     local_include_dirs: ["tests"],
-    include_dirs: ["bionic/libc", "bionic"],
+    include_dirs: [
+        "bionic/libc",
+        "bionic"
+    ],
+    header_libs: [
+        "bionic_libc_platform_headers",
+    ],
 
     cflags: [
         "-Wall",
diff --git a/libc/malloc_hooks/tests/malloc_hooks_tests.cpp b/libc/malloc_hooks/tests/malloc_hooks_tests.cpp
index 86e20ea..1858781 100644
--- a/libc/malloc_hooks/tests/malloc_hooks_tests.cpp
+++ b/libc/malloc_hooks/tests/malloc_hooks_tests.cpp
@@ -38,7 +38,7 @@
 
 #include <gtest/gtest.h>
 
-#include <private/bionic_malloc.h>
+#include <bionic/malloc.h>
 #include <private/bionic_malloc_dispatch.h>
 #include <tests/utils.h>