debuggerd: fix missed use of ptrace(PTRACE_ATTACH). am: 8b6b654a5f am: fe59793375 am: 073f731836 am: 647ec18a9d  -s ours am: 364188b9d8 am: a200a4d592
am: 070328f594

Change-Id: I1a5dba4602f230cec1acaa4aaf2db63ce2434c3a