Add HAL definition for graphics buffer allocator

It differs from gralloc1.h in that

 - buffer descriptors are created from a struct, BufferDescriptorInfo, to
   reduce round trips
 - testAllocate is a function of its own
 - buffer allocation and export are two different steps
 - reference counting and buffer mapping are moved to gralloc-mapper
 - BAD_HANDLE is renamed to BAD_BUFFER
 - GRALLOC1_CONSUMER_USAGE_FOREIGN_BUFFERS is removed
 - CPU_{READ,WRITE}_OFTEN no longer implies CPU_{READ,WRITE}

Test: make android.hardware.graphics.allocator@2.0

Change-Id: Ibe9367d5b1701c0e1009da829f27fed0f7d98828
diff --git a/Android.bp b/Android.bp
index 65febd3..727054c 100644
--- a/Android.bp
+++ b/Android.bp
@@ -3,6 +3,7 @@
     "audio/common/2.0",
     "audio/effect/2.0",
     "benchmarks/msgq/1.0",
+    "graphics/allocator/2.0",
     "memtrack/1.0",
     "memtrack/1.0/default",
     "nfc/1.0",