libgui/SurfaceFlinger: Add getConsumerName

Adds a getConsumerName method to IGraphicBufferProducer and Surface.
Currently, the name is cached inside of IGBP and is update on connect
and dequeueBuffer, which should be good enough for most uses.

Bug: 6667401
Change-Id: I22c7881d778e495cf8276de7bbcd769e52429915
diff --git a/libs/gui/Surface.cpp b/libs/gui/Surface.cpp
index aeb56e0..df0661c 100644
--- a/libs/gui/Surface.cpp
+++ b/libs/gui/Surface.cpp
@@ -111,6 +111,10 @@
     return result;
 }
 
+String8 Surface::getConsumerName() const {
+    return mGraphicBufferProducer->getConsumerName();
+}
+
 int Surface::hook_setSwapInterval(ANativeWindow* window, int interval) {
     Surface* c = getSelf(window);
     return c->setSwapInterval(interval);