regen stale metrics.descriptor

(presubmits don't catch when metrics are changed without a corresponding
tools/gen_all invocation, I never got around to checking why)

Change-Id: I3679e91dbe289b094374831b53e8940573f611e3
diff --git a/python/perfetto/trace_processor/metrics.descriptor b/python/perfetto/trace_processor/metrics.descriptor
index 9b3d2e7..e866358 100644
--- a/python/perfetto/trace_processor/metrics.descriptor
+++ b/python/perfetto/trace_processor/metrics.descriptor
Binary files differ