BufferQueue: clean up buffer counting

This change is a clean up of some of the handling of the maximum number of
buffers that are allowed at once.  It mostly renames a few member variables and
methods, but it includes a couple small refactorings.

Change-Id: I9959310f563d09583548d4291e1050a7bbc7d87d
diff --git a/services/surfaceflinger/Layer.cpp b/services/surfaceflinger/Layer.cpp
index 4c82f91..ea1bc54 100644
--- a/services/surfaceflinger/Layer.cpp
+++ b/services/surfaceflinger/Layer.cpp
@@ -104,9 +104,9 @@
 
 #ifdef TARGET_DISABLE_TRIPLE_BUFFERING
 #warning "disabling triple buffering"
-    mSurfaceTexture->setBufferCountServer(2);
+    mSurfaceTexture->setDefaultMaxBufferCount(2);
 #else
-    mSurfaceTexture->setBufferCountServer(3);
+    mSurfaceTexture->setDefaultMaxBufferCount(3);
 #endif
 }