Fix some inappropriate docstring, like:
1. "Gets detailed information for a stack" as the docstring for show() in
events.py
2. "Lists summary information for all resources" as the docstring for
index() in events.py
3. "Gets detailed information for a stack" as the docstring for show() in
resources.py
4. "Gets detailed information for a stack " as the docstring for
metadata() in resources.py
Change-Id: I38fc6a18224d1537bf6981ba60bffc31768b7443
Closes-Bug: #1261615