Revert "ANDROID: Incremental fs: Add .incomplete folder"

This reverts commit 5b188fc3.

Set incfs back to rvc shipping incfs

Bug: 178509184
Test: incfs_test passes
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Change-Id: Icc3189af926bf815d8dc7ca337f2010ae59bbad1