manifest: switch to omni external/skia

Change-Id: I95ac5a4cfd723c091ae0efae455476f524a7cee4
diff --git a/remove.xml b/remove.xml
index 508ea2d..b938151 100644
--- a/remove.xml
+++ b/remove.xml
@@ -65,6 +65,7 @@
   <remove-project name="platform/external/mksh" />
   <remove-project name="platform/external/tinycompress" />
   <remove-project name="platform/external/selinux" />
+  <remove-project name="platform/external/skia" />
   <remove-project name="platform/external/toybox" />
 
   <remove-project name="platform/frameworks/av" />