docker: Exclude .changes files when collecting debs

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Change-Id: I7badee212bd05178a30a6ff4c73c8d62258d2c1d
Reviewed-on: https://bazel-review.googlesource.com/#/c/2841
MOS_MIGRATED_REVID=114330213

tools/build_defs/docker/docker.bzl

diff --git a/tools/build_defs/docker/docker.bzl b/tools/build_defs/docker/docker.bzl
index 9ca4fc8..0d5c40b 100644
--- a/tools/build_defs/docker/docker.bzl
+++ b/tools/build_defs/docker/docker.bzl
@@ -100,7 +100,7 @@
   args += ["--file=%s=%s" % (f.path, _dest_path(f, data_path))
            for f in ctx.files.files]
   args += ["--tar=" + f.path for f in ctx.files.tars]
-  args += ["--deb=" + f.path for f in ctx.files.debs]
+  args += ["--deb=" + f.path for f in ctx.files.debs if f.path.endswith(".deb")]
   args += ["--link=%s:%s" % (k, ctx.attr.symlinks[k])
            for k in ctx.attr.symlinks]