Revert "ANDROID: Incremental fs: Add INCFS_IOC_GET_BLOCK_COUNT"

This reverts commit 1652f264.

Set incfs back to rvc shipping incfs

Bug: 178509184
Test: incfs_test passes
Signed-off-by: Paul Lawrence <paullawrence@google.com>
Change-Id: Ifdbdbffee413a16e8c222da60a371ac95797501a