[dogfooding][cleanup] Use static inner class clean up for
tools.resources
code

Using this cleanup brings:
- It reviews the feature
 - For optimization: small memory usage reduction as the outer pointer
is removed

Change-Id: I3a6f3188ddd339ddba7bb1a0a7d2964bdf41aafd
Signed-off-by: Lars Vogel <Lars.Vogel@vogella.com>