[TestLldbGdbServer] Up sleep duration to 1min in the inferior thread_func.

Summary:
The current sleep duration is not sufficient for Android.

[[ Its a completely different investigation as to why Android needs longer
   sleep durations for this test. ]]

Test Plan: dotest.py -p TestLldbGdbServer on Android and local linux.

Reviewers: chaoren

Reviewed By: chaoren

Subscribers: tberghammer, lldb-commits

Differential Revision: http://reviews.llvm.org/D9926

llvm-svn: 237981