Add platform/prebuilts/android-emulator

Change-Id: Ifcd9e4bebc156be815fb64b9efe3d29b2a23ab91
diff --git a/default.xml b/default.xml
index c18d155..4e3aab4 100644
--- a/default.xml
+++ b/default.xml
@@ -375,6 +375,7 @@
   <project path="packages/wallpapers/NoiseField" name="platform/packages/wallpapers/NoiseField" />
   <project path="packages/wallpapers/PhaseBeam" name="platform/packages/wallpapers/PhaseBeam" />
   <project path="pdk" name="platform/pdk" groups="pdk" />
+  <project path="prebuilts/android-emulator" name="platform/prebuilts/android-emulator" />
   <project path="prebuilts/clang/darwin-x86/3.1" name="platform/prebuilts/clang/darwin-x86/3.1" groups="pdk,darwin" />
   <project path="prebuilts/clang/darwin-x86/3.2" name="platform/prebuilts/clang/darwin-x86/3.2" groups="pdk,darwin" />
   <project path="prebuilts/clang/darwin-x86/arm/3.3" name="platform/prebuilts/clang/darwin-x86/arm/3.3" groups="darwin,arm" />