Introduce new UI_MODE_TYPE_VR_HEADSET and qualifier.

Bug: 30989383
Test: Unit test for aapt2
Change-Id: I66dc65af6327b94fed74538bee08cada0b8be4fa
diff --git a/libs/androidfw/ResourceTypes.cpp b/libs/androidfw/ResourceTypes.cpp
index 907d914..7fbfffe 100644
--- a/libs/androidfw/ResourceTypes.cpp
+++ b/libs/androidfw/ResourceTypes.cpp
@@ -2994,6 +2994,9 @@
             case ResTable_config::UI_MODE_TYPE_WATCH:
                 res.append("watch");
                 break;
+            case ResTable_config::UI_MODE_TYPE_VR_HEADSET:
+                res.append("vrheadset");
+                break;
             default:
                 res.appendFormat("uiModeType=%d",
                         dtohs(screenLayout&ResTable_config::MASK_UI_MODE_TYPE));