Implement FUSE_WRITE command in app fuse.

The CL adds a handler for FUSE_WRITE command which invokes a Java
handler.

BUG=23093747

Change-Id: I1903fca6b5663e6241ad540a89fe812310ba6810
(cherry picked from commit 35693da25af11583053d4af6a70d4acbf446978d)
5 files changed