Preventing launcher crashes due to low disk space.

In case of low disk space, all write operations to the IconCache are
silently ignored. This will not affect the Launcher behavior and
user will still see the latest icons, but in some cases, icon loading
would appear slow

Bug: 24585352
Change-Id: I85ccc519046fc3708403388bba89e019a3f2ce3d
3 files changed