Does not elegantly handle version upgrades

[Brantone]

This is a knock-on from https://github.com/gildegoma/chef-android-sdk/issues/12

When upgrading, components do not get installed because the guard is misconfigured.

The call at https://github.com/gildegoma/chef-android-sdk/blob/master/recipes/default.rb#L109 only works if the version hasn't changed ...

For example, if version 24.1.2 is installed, then upgrade to 24.4, because the it's a symlink delete and recreate, not an overwrite, it thinks that "temp" exists due to order of execution during converge.

Might be able to circumvent by not doing symlink.

[Brantone]

…. actually … that guard also prevents an update to components list … so, another use-case for #12.