SurfaceFlinger: Add ClientCache dumps

Can be useful in debugging buffer leaks.

Bug: 176691195
Test: Existing tests pass
Change-Id: I8b318f272a7da3dde76d9153b21ced94127f0d8b
diff --git a/services/surfaceflinger/SurfaceFlinger.cpp b/services/surfaceflinger/SurfaceFlinger.cpp
index 77f4009..4f93b89 100644
--- a/services/surfaceflinger/SurfaceFlinger.cpp
+++ b/services/surfaceflinger/SurfaceFlinger.cpp
@@ -4849,6 +4849,8 @@
 
     getRenderEngine().dump(result);
 
+    result.append("ClientCache state:\n");
+    ClientCache::getInstance().dump(result);
     DebugEGLImageTracker::getInstance()->dump(result);
 
     if (const auto display = getDefaultDisplayDeviceLocked()) {