Fix ressource leak in getFileCrC

Change-Id: If8a63fa355664d360aab6ecba92c82cd56b745b8
Make sure ThemeConfig is non-null when loading resources

When the device boots into safemode, the theme config will end up
being null and we need to check that prior to using it to retrieve
resources for the StatusBarIconView

This fixes CYAN-5009

Change-Id: I1a90bc9f9c65cb41a6e58947bbd1b6d7728a952b