graphics: add composer 2.2 default impl

This adds

  android.hardware.graphics.composer@2.2-hal
  android.hardware.graphics.composer@2.2-passthrough
  android.hardware.graphics.composer@2.2-service

The -hal module makes it easier to write composer 2.2 HAL and is
reusable by vendors.  The -passthrough module provides a HwcHal
class that implements ComposerHal 2.2 on top of hwcomposer2, and is
also resuable by vendors.  Finally, the -service module provides a
(stub) default implementation.

Test: boots and VTS
Change-Id: I4f940a9dea656abc7d9d485bf48d852c13d2ed56
diff --git a/graphics/composer/2.2/default/android.hardware.graphics.composer@2.2-service.rc b/graphics/composer/2.2/default/android.hardware.graphics.composer@2.2-service.rc
new file mode 100644
index 0000000..a41d902
--- /dev/null
+++ b/graphics/composer/2.2/default/android.hardware.graphics.composer@2.2-service.rc
@@ -0,0 +1,6 @@
+service vendor.hwcomposer-2-2 /vendor/bin/hw/android.hardware.graphics.composer@2.2-service
+    class hal animation
+    user system
+    group graphics drmrpc
+    capabilities SYS_NICE
+    onrestart restart surfaceflinger