Revert "ANDROID: Incremental fs: Fix initialization, use of bitfields"

This change was never cherry-picked to other branches,
is just syntactic sugar, and clashes with another change. Revert,
and then apply cleanly over all branches as needed.

This reverts commit 2664a43d.

Change-Id: I51dca9cb046cc15302c22e8f73e58dcf4849f84d
Signed-off-by: Paul Lawrence <paullawrence@google.com>