Add tracing thread for RenderEngine's fences

RenderEngine doesn't always render to FramebufferSurface, so tracing
that is built into BufferQueue is lost. Add a tracing thread so that
screenshots and caching can also have GPU work traced.

Bug: 280684246
Bug: 269822044
Test: perfetto
Change-Id: I067430f6b6b588dd3046d1cf66d0a3fc8465746d
diff --git a/libs/gui/Android.bp b/libs/gui/Android.bp
index 80fed98..bf34987 100644
--- a/libs/gui/Android.bp
+++ b/libs/gui/Android.bp
@@ -217,6 +217,7 @@
         "DebugEGLImageTracker.cpp",
         "DisplayEventDispatcher.cpp",
         "DisplayEventReceiver.cpp",
+        "FenceMonitor.cpp",
         "GLConsumer.cpp",
         "IConsumerListener.cpp",
         "IGraphicBufferConsumer.cpp",