Generate build timing metrics to proto format file

Test: Dumped the text formated based metrics file to out dir,
and checked the file.
Bug: b/63815990

Change-Id: Iff476f72a0be74eb53b6b26ef468d11c0f24a404
diff --git a/ui/metrics/metrics_proto/regen.sh b/ui/metrics/metrics_proto/regen.sh
new file mode 100755
index 0000000..343c638
--- /dev/null
+++ b/ui/metrics/metrics_proto/regen.sh
@@ -0,0 +1,3 @@
+#!/bin/bash
+
+aprotoc --go_out=paths=source_relative:. metrics.proto