manifest: add system/extras

Change-Id: I73f242e1735c9e28dc990bacaefe554ab915a882
diff --git a/remove.xml b/remove.xml
index c1c66f8..216eafc 100644
--- a/remove.xml
+++ b/remove.xml
@@ -125,6 +125,7 @@
 
   <remove-project name="platform/system/bt" />
   <remove-project name="platform/system/core" />
+  <remove-project name="platform/system/extras" />
   <remove-project name="platform/system/libhidl" />
   <remove-project name="platform/system/media" />
   <remove-project name="platform/system/nfc" />