Removing the ability to get native instrumentation as part of nav dump

This is to be able to remove ANDROID_INSTRUMENTATION code.

Note that it would only print useful information if webcore
was compiled with ANDROID_INSTRUMENTATION on.

There is an open bug for problems with ANDROID_INSTRUMENTATION:
http://b/issue?id=2816327

Needs Browser CL:
https://android-git.corp.google.com/g/#/c/149442

Change-Id: Ie8c3c3a08a8bb15936831e25faac3155906bae70