Debuggerd: Extend crash_dump timeout to 5 seconds

Some processes have lots of threads and minidebug-info. Unwinding
these can take more than the original two seconds.

Bug: 62828735
Test: m
Test: debuggerd_test
Test: adb shell kill -s 6 `pid system_server`
Change-Id: I0041bd01753135ef9d86783a3c6a5cbca1c5bbad