traced: add metatrace support via in-process producer (folding in LazyProducer)

Replacing LazyProducer with a BuiltinProducer, with an extra data source for
perfetto metatrace. The metatrace source has "notify_on_stop", and does an
extra flush during stop to commit the events happening around the flush time.

Change-Id: I5d72398a3154d769cd9cd8cac0caf5929462217b
diff --git a/Android.bp b/Android.bp
index 8ed4fdc..3d27af3 100644
--- a/Android.bp
+++ b/Android.bp
@@ -320,7 +320,7 @@
     "src/traced/probes/probes_producer.cc",
     "src/traced/probes/ps/process_stats_data_source.cc",
     "src/traced/probes/sys_stats/sys_stats_data_source.cc",
-    "src/traced/service/lazy_producer.cc",
+    "src/traced/service/builtin_producer.cc",
     "src/traced/service/service.cc",
     "src/tracing/api_impl/consumer_api.cc",
     "src/tracing/core/chrome_config.cc",
@@ -3550,8 +3550,8 @@
     "src/traced/probes/ps/process_stats_data_source_unittest.cc",
     "src/traced/probes/sys_stats/sys_stats_data_source.cc",
     "src/traced/probes/sys_stats/sys_stats_data_source_unittest.cc",
-    "src/traced/service/lazy_producer.cc",
-    "src/traced/service/lazy_producer_unittest.cc",
+    "src/traced/service/builtin_producer.cc",
+    "src/traced/service/builtin_producer_unittest.cc",
     "src/traced/service/service.cc",
     "src/tracing/core/chrome_config.cc",
     "src/tracing/core/commit_data_request.cc",