DO NOT MERGE Remove java.io.tmpdir assignment in AndroidRuntime.

This value is overridden by the framework anyway
(see ActivityThread.handleBindApplication). Besides,
it doesn't seem like a great idea to let tools clutter
/sdcard/ with temp files.

(cherry picked from commit b3802a8e)

Bug: 13763685
Bug: 13763900

Change-Id: I26c710cbea7397f89e6103e54a73044a87da95b1