metropolis/proto: move log-related types to common

Having them in API is kinda weird, especially as we're
generating/parsing them from a few libraries already.

Change-Id: I87b4b51f151443c60b87e3e50753c395fcf6e845
Reviewed-on: https://review.monogon.dev/c/monogon/+/1437
Tested-by: Jenkins CI
Reviewed-by: Lorenz Brun <lorenz@monogon.tech>
diff --git a/metropolis/pkg/logtree/BUILD.bazel b/metropolis/pkg/logtree/BUILD.bazel
index 5c4237c..2e2f07e 100644
--- a/metropolis/pkg/logtree/BUILD.bazel
+++ b/metropolis/pkg/logtree/BUILD.bazel
@@ -20,7 +20,7 @@
     visibility = ["//metropolis:__subpackages__"],
     deps = [
         "//metropolis/pkg/logbuffer",
-        "//metropolis/proto/api",
+        "//metropolis/proto/common",
         "@com_github_mitchellh_go_wordwrap//:go-wordwrap",
         "@org_golang_google_protobuf//types/known/timestamppb",
     ],