Fix boto initialization

boto test skip(service considered enabled) mechanism based on global
variables, set by the generic_setup_package.
When the tesresources is introduced for handling initialization,
the skip logic frequently sees the default disabled values.

Every boto test cases depends on base class, which static (class)
attribute initialization done, before any setUpClass checking the global
variables.

This initialization is happens only once, and visible by all subclasses.

A possible next step (after this change), to have the
generic_setup_package to return, with a dict contains the conclusion
about the testing and configured variables, it will be visible for all
subclasses.

Change-Id: Idc0a1b1ce0e78f7837c3f3b3a2e0593750861fa7
Merge "Fix boto initialization"