[roll] Roll fuchsia [fxt] Implement the Rest of the FXT Events

Implements:
- DurationEvent
- DurationBeginEvent
- DurationEndEvent
- AsyncBeginEvent
- AsyncInstantEvent
- AsyncEndEvent
- FlowBeginEvent
- FlowStepEvent
- FlowEndEvent

This events are implemented as described by the fxt documentation [1]

This is is a reimplementation of the apis
ulib/trace-engine/context_api.cc[2] that are buffer and writer
independent.

[1] https://fuchsia.dev/fuchsia-src/reference/tracing/trace-format#event-record
[2] https://cs.opensource.google/fuchsia/fuchsia/+/master:zircon/system/ulib/trace-engine/context_api.cc;l=848;drc=0b95ec1c99b1378175e59f5a4f7ef79f6d484b0a

Original-Bug: 98177
Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/675697
Original-Revision: c3fc68837e70aa28fcbd8659fa1eb0d28c7fb0bd
GitOrigin-RevId: b809220219b7bf942c08fac9581f7055f7e6aa91
Change-Id: I85c58527886990932554c991a459644b5743f9dc
diff --git a/stem b/stem
index 7287e87..70af0cc 100644
--- a/stem
+++ b/stem
@@ -10,7 +10,7 @@
              githooks=""
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="30b11de1a6d20a180d54ee254550f5924e516c61"/>
+             revision="c3fc68837e70aa28fcbd8659fa1eb0d28c7fb0bd"/>
   </projects>
   <hooks>
     <hook name="install-environment"