SurfaceFlinger: add thread name to OneShotTimer

Test: interact with device and observe systraces
Bug: 170665374
Change-Id: I55af2ec268dfaa10c570876aeeb63e602ec08ef7
diff --git a/services/surfaceflinger/RegionSamplingThread.cpp b/services/surfaceflinger/RegionSamplingThread.cpp
index b7b7e46..2511eb3 100644
--- a/services/surfaceflinger/RegionSamplingThread.cpp
+++ b/services/surfaceflinger/RegionSamplingThread.cpp
@@ -175,6 +175,7 @@
         mScheduler(scheduler),
         mTunables(tunables),
         mIdleTimer(
+                "RegionSamplingIdleTimer",
                 std::chrono::duration_cast<std::chrono::milliseconds>(
                         mTunables.mSamplingTimerTimeout),
                 [] {}, [this] { checkForStaleLuma(); }),