When calculating memory cache size, use Runtime.maxMemory() instead
of getMemoryClass() which is a more accurate value of available VM
heap size.
Also bump target and build SDK to 17.
Bug: 7988323
Change-Id: I4b94688b3800d958ffbe03ee9a2a620982483d3d
Changes:
-Use updated versions of ImageWorker & ImageCache from I/O 2012 app
-Use copied DiskLruCache from system (rather than custom)
-Use copied AsyncTask from system (to keep behavior consistent)
-Ensure no strict mode violations or lint errors
-Other misc bug fixes
-Move single-use static methods in Utils to corresponding class
Change-Id: If21e045db1e1a80391169f3c9c9258d48345ab6b