remove erroneous file

Doc update: new Volley class

Change-Id: Ife3a9a64439e07aaaf92a22adc6d1678138caf7d

# Please enter the commit message for your changes. Lines starting

# with '#' will be ignored, and an empty message aborts the commit.

# On branch volley

# Changes to be committed:

#	new file:   docs/html/images/training/volley-request.png

#	modified:   docs/html/training/basics/network-ops/connecting.jd

#	modified:   docs/html/training/basics/network-ops/index.jd

#	modified:   docs/html/training/training_toc.cs

#	new file:   docs/html/training/volley/index.jd

#	new file:   docs/html/training/volley/request-custom.jd

#	new file:   docs/html/training/volley/request.jd

#	new file:   docs/html/training/volley/requestqueue.jd

#	new file:   docs/html/training/volley/setup.jd

#	new file:   docs/html/training/volley/simple.jd

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