Initial trace-based startup metric in AOSP

- Partitions the trace into spans based on the initial intent
- Correlates these spans with an actual launching event
- Breaks down main thread by task state

Bug: b/132775271
Change-Id: I14765c5591f787f269d47b5fe217e458de2eb28e
diff --git a/protos/BUILD b/protos/BUILD
index bf721d9..473c8e4 100644
--- a/protos/BUILD
+++ b/protos/BUILD
@@ -177,6 +177,7 @@
     name = "metrics_android_zero",
     srcs = [
         "perfetto/metrics/android/mem_metric.proto",
+        "perfetto/metrics/android/startup_metric.proto",
     ],
 )