am efe20150: add free space on system and cache to free_storage_left log event

Merge commit 'efe2015084676ceff5d5ea1d1ebffaa5deb59a05' into eclair

* commit 'efe2015084676ceff5d5ea1d1ebffaa5deb59a05':
  add free space on system and cache to free_storage_left log event
tree: cd9eb4f55fcd64b630f6ec7cd76c33e69e4165d1
  1. liblog/
  2. logcat/
  3. logwrapper/