paygen_build_lib: Temporarily disable peach-pit FSI full AU tests.

The FSI candidates for peach-pit don't play well with our lab, so that
full payload tests in the lab fail, breaking the DUTs. This CL
temporarily drops this test for peach-pit

This hack should be reverted once crbug.com/462320 is fixed.

BUG=chromium:460174
BUG=chromium:462320
TEST=(1) unittests.
     (2) `crostools/bin/paygen_build --output_dir /tmp/payloads/ \
            -c canary-channel -b peach-pit --version xxxx.xx.xx`
         and verify that no FSI tests would be launched.

Change-Id: I601520b1f2ba7a0f269d99f503e22173af7905d5
Reviewed-on: https://chromium-review.googlesource.com/254372
Tested-by: Prathmesh Prabhu <pprabhu@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
(cherry picked from commit 8fb84505c2f7793d275a729f21fbe70366a35f54)
Reviewed-on: https://chromium-review.googlesource.com/254476
Reviewed-by: Richard Barnette <jrbarnette@chromium.org>
diff --git a/lib/paygen/paygen_build_lib.py b/lib/paygen/paygen_build_lib.py
index 8a4b31e..929c46b 100644
--- a/lib/paygen/paygen_build_lib.py
+++ b/lib/paygen/paygen_build_lib.py
@@ -533,8 +533,9 @@
     """
     # TODO(dgarrett): Switch to JSON mechanism in _DiscoverAllFsiBuilds
     #   after it's in production, and after we clear the change with the TPMs.
-    #
     #   At that time, check and ignore FSIs without the is_delta_supported flag.
+    # TODO(pprabhu): Can't switch to _DiscoverAllFsiBuilds till the HACK there
+    #   is removed.
 
     # FSI versions are only defined for the stable-channel.
     if self._build.channel != 'stable-channel':
@@ -568,6 +569,13 @@
       may be empty.
     """
     results = []
+    # XXX:HACK -- FSI builds for this board is known to brick the DUTs in the
+    # lab. As a workaround, we're dropping test coverage for this board
+    # temporarily (crbug.com/460174).
+    # TODO(pprabhu) Remove hack once we have a real solution (crbug.com/462320).
+    if self._build.board == 'peach-pit':
+      return results
+
     contents = json.loads(gslib.Cat(FSI_URI))
 
     for fsi in contents.get('fsis', []):