Products using 16KB kernel may wish to boot into 16KB mode
directly. To do this, these targets would need to use ext4
as their default fs type for /data and /metadata . Add
a build time flag which would install ext4 fstabs.
Test: th
Bug: 339337171
Change-Id: I53de1599bbff583b45ca2bf6d3e3efb83957913e