Remove repo 1.9.4 compatibility code.
Remove repo 1.9.4 compatibility code.

We now have >=v1.9.6 in use which fixes the bugs in question;
further, we force a self update as the first step, so v1.9.4
issues no longer need to be suppressed.

BUG=None
TEST=manual validation (specifically validation of v1.9.6)

Change-Id: Ib1acb181c4053f1dd9eec8691dde1c0cd03b00dc
Reviewed-on: https://gerrit.chromium.org/gerrit/28446
Tested-by: Brian Harring <fdc2d0a2e2340b623587cee5ea8dff425d1eb1f3@chromium.org>
Reviewed-by: David James <f231dc574bbeb62604660cbc162d1b8642a0a3af@chromium.org>
Reviewed-by: Ryan Cui <5ce1592d53754a87a44fc2eb7b63d5f77cf50fdb@chromium.org>
Commit-Ready: Brian Harring <fdc2d0a2e2340b623587cee5ea8dff425d1eb1f3@chromium.org>

zhang0137/chromite,coreos/chromite,coreos/chromite,zhang0137/chromite,chadversary/chromiumos.chromite,coreos/chromite,bpsinc-native/src_third_party_chromite,bpsinc-native/src_third_party_chromite,chadversary/chromiumos.chromite,zhang0137/chromite,bpsinc-native/src_third_party_chromite