Malloc debug: fix mutex deadlock issue

When we enable free_track option, one thread is in AddFreed->RemoveBacktrace
flow (hold free_pointer_mutex_ first and try to lock frame_mutex_), and
other thread do fork and enter PrepareFork flow (hold frame_mutex_ first
and try to lock free_pointer_mutex_), this situation may result in mutex
deadlock issue.

Bug: 127733115
Test: build pass and stress test pass
Change-Id: Ie5fcc4ef6c169372ad73d81978cfb2a726b6c03e