[Android] fix white screen cause deadlock

[lucky-chen]

• changlog
  • fix white screen cause deadlock (crash_handler.cpp)
  • add switch for open/close fixlogic

handleSignal maybe cause sig delivered deadLock,and maybe block weexCoreThread on ipc，then cause whiteScreen or other issue unless restart app

• bug
  • cause 1: sigaction handler should use async-signal-safe func
  • cause 2:other logic crash or dl.
• solution:
  • google breakPad dump crash on a new process to avoid bugs.
  • tmp solution (we use): setTimeout 1s,force exit on handleExitAlarm(if has deadLock)

[weex-bot]

	Warnings
⚠️	No Changelog changes! - Can you add a Changelog? To do so,append your changes to the changelog.md
⚠️	Current pr not bind the milestone
⚠️	If your PR is about fixing a bug excluding crash the code,you should add the demo link in the PR description. Demo link: http://dotwe.org/vue

	Messages
📖	danger test finished.

Generated by 🚫 dangerJS against a8041fc

[Darin726]

LGTM