tracing: Send triggers on connection

The newly introduced ActivateTriggers only sends triggers to the
currently connected backends.

Since perfetto::Tracing::Initialize() is not blocking, it can happen
that a backend takes a while to connect.

If a registered backend is not connected when ActivateTriggers is
called, the system will remember that and send the trigger when the
backend connects.

An expiration must be provided to avoid sending triggers if the tracing
service takes too much to connect.

Bug: 259929612
Change-Id: I183ef3ae04e960797adc835e137f854d0ebd409d
diff --git a/Android.bp b/Android.bp
index 09c13f0..640af7c 100644
--- a/Android.bp
+++ b/Android.bp
@@ -2027,6 +2027,7 @@
         ":perfetto_src_tracing_core_service",
         ":perfetto_src_tracing_core_test_support",
         ":perfetto_src_tracing_in_process_backend",
+        ":perfetto_src_tracing_integrationtests",
         ":perfetto_src_tracing_ipc_common",
         ":perfetto_src_tracing_ipc_consumer_consumer",
         ":perfetto_src_tracing_ipc_default_socket",
@@ -10507,6 +10508,14 @@
     ],
 }
 
+// GN: //src/tracing:integrationtests
+filegroup {
+    name: "perfetto_src_tracing_integrationtests",
+    srcs: [
+        "src/tracing/internal/tracing_muxer_impl_integrationtest.cc",
+    ],
+}
+
 // GN: //src/tracing/ipc:common
 filegroup {
     name: "perfetto_src_tracing_ipc_common",