Declare dlmalloc as a cc_library_headers

This change is needed so dlmalloc can be included into libart
(art/runtime/gc/allocator/art-dlmalloc.{h, cc}) through the
include directory (rather than via a direct relative path
inclusion, as it is at the moment).

Bug: 236243696
Test: lunch aosp_cf_x86_64_phone-userdebug && m
Change-Id: Ic6f84404a27b0ad93e161e6bd080331d0c6d6439
4 files changed