Properly describe exception

Previously we used DetachCurrentThread which raised a SIGABRT from
within ART. The new approach is to use ExceptionDescribe and exit.

Bug: 20640601

(cherry picked from commit d12065f581defd9e8199593e85aa2036a0713684)

Change-Id: I00126b678ff296e0076247554af8328fe2767038
1 file changed