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