Automatic merge from submit-queue

Fixed typos and issues in examples/volumes/glusterfs/README.md

**What this PR does / why we need it**:

This PR updates the GlusterFS `README.md` to fix several typos, outdated documentation and examples that did not work anymore.

**Which issue this PR fixes** 

None

**Special notes for your reviewer**:

None

**Release note**:

`release-note-NONE`