Report traceback with details only in the case where unexpected exception occurs in api-server
(i.e ignore reporting tracebacks details for bottle.abort). Add unit test for same.

Fixes bug: 1346459

Change-Id: I5dbb2387d4046210958191845f2a66675284ad55
Merge "Report traceback with details only in the case where unexpected exception occurs in api-server (i.e ignore reporting tracebacks details for bottle.abort). Add unit test for same."