Introduce new UI_MODE_TYPE_VR_HEADSET and qualifier.

Bug: 30989383
Test: Unit test for aapt2
Change-Id: I66dc65af6327b94fed74538bee08cada0b8be4fa
diff --git a/tools/aapt2/SdkConstants.h b/tools/aapt2/SdkConstants.h
index 9b38ecb..5352b53 100644
--- a/tools/aapt2/SdkConstants.h
+++ b/tools/aapt2/SdkConstants.h
@@ -45,6 +45,9 @@
   SDK_LOLLIPOP = 21,
   SDK_LOLLIPOP_MR1 = 22,
   SDK_MARSHMALLOW = 23,
+  SDK_NOUGAT = 24,
+  SDK_NOUGAT_MR1 = 25,
+  SDK_O = 26, // STOPSHIP Replace with real version
 };
 
 size_t FindAttributeSdkLevel(const ResourceId& id);