Update hwcomposer include paths

In preparation of new hwcomposer interface, updating
existing includes to include specific version.
Bug: 71513561
Test: compile

Change-Id: Iab13368f782067f255f7dee5318bfd57872f30dd
diff --git a/services/vr/hardware_composer/Android.bp b/services/vr/hardware_composer/Android.bp
index 76ec42d..063d83c 100644
--- a/services/vr/hardware_composer/Android.bp
+++ b/services/vr/hardware_composer/Android.bp
@@ -32,6 +32,10 @@
     "libutils",
   ],
 
+  header_libs: [
+    "android.hardware.graphics.composer@2.1-command-buffer",
+  ],
+
   export_static_lib_headers: [
     "libhwcomposer-client",
   ],