Revert "Update platform_CrosDisksFilesystem ext2/3/4 tests."

This reverts commit dc6e31a09ca866b75bd06caa6323828b6f6ec5f0.

CL:223391 re-enables the support of ext2/3/4 filesystem in cros-disks.
This CL updates platform_CrosDisksFilesystem ext2/3/4 tests to verify
that mounting of ext2/3/4 filesystems via cros-disks succeeds again.

BUG=chromium:315401
CQ-DEPEND=CL:223391
TEST=Run platform_CrosDisksFilesystem tests.

Change-Id: I09d22b7d3ef9bf7b3b589c0e3d6939918c102f4b
Reviewed-on: https://chromium-review.googlesource.com/223383
Reviewed-by: mukesh agrawal <quiche@chromium.org>
Commit-Queue: Ben Chan <benchan@chromium.org>
Tested-by: Ben Chan <benchan@chromium.org>
4 files changed