Refactor IonBuffer to use GraphicBuffer

- Replace gralloc0 based implementation with GraphicBuffer implementation.
- Removed incompatible ion-buffer unit-tests.
- Added libui dependencies to dependants.

Bug: 34879523
Test: Tested on Lucid, validated graphics and poses are working
Change-Id: I49a129f269d54c81bda93b44d879d4b8dee2006a
diff --git a/services/vr/bufferhubd/Android.mk b/services/vr/bufferhubd/Android.mk
index 0db909c..c1a0b6f 100644
--- a/services/vr/bufferhubd/Android.mk
+++ b/services/vr/bufferhubd/Android.mk
@@ -34,7 +34,8 @@
 	liblog \
 	libsync \
 	libutils \
-	libgui
+        libgui \
+        libui
 
 include $(CLEAR_VARS)
 # Don't strip symbols so we see stack traces in logcat.