Enable call stacks in crash reports tests

This is a follow up change to enable the tests for the call stacks in
crash reports feature and address the flakiness.

The problem is that when we simulate an unresponsive renderer to
start the workflow to collect the js call stack. The next call which
is to shut down the renderer process may execute and complete before
we can retrieve the call stack.

Bug: 40268201
Change-Id: Ia79aa02b5e63f89afe35134d0afdb65a008c3496
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5422052


Reviewed-by: Adam Rice <ricea@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Commit-Queue: Issack John <issackjohn@microsoft.com>
Cr-Commit-Position: refs/heads/main@{#1283384}