sandersr: drop custom display flags

* TARGET_USES_OVERLAY and USE_OPENGL_RENDERER are largely deprecated
* Don't set triple buffering, it introduces latency
* Don't use custom VSYNC offsets

Change-Id: If2892c83726c3558a96b28a8404f49982ebb9ba0

BoardConfig.mk

@@ -154,7 +154,6 @@ WITH_DEXPREOPT := true
 
 # Display
 BOARD_USES_ADRENO := true
-NUM_FRAMEBUFFER_SURFACE_BUFFERS := 3
 OVERRIDE_RS_DRIVER := libRSDriver_adreno.so
 TARGET_USES_C2D_COMPOSITION := true
 TARGET_USES_GRALLOC1 := true