Revert "Add external/xdelta3 and external/syspatch"

This reverts commit d7e5ea0d0c.
Change-Id: I89f89c63cb5473f75ac738d0db1cfde8d7e7cd13

default.xml

@@ -224,7 +224,6 @@
   <project path="external/strace" name="platform/external/strace" />
   <project path="external/stressapptest" name="platform/external/stressapptest" />
   <project path="external/svox" name="platform/external/svox" />
-  <project path="external/syspatch" name="platform/external/syspatch" />
   <project path="external/tagsoup" name="platform/external/tagsoup" />
   <project path="external/tcpdump" name="platform/external/tcpdump" />
   <project path="external/timezonepicker-support" name="platform/external/timezonepicker-support" />
@@ -238,7 +237,6 @@
   <project path="external/webp" name="platform/external/webp" />
   <project path="external/webrtc" name="platform/external/webrtc" groups="pdk" />
   <project path="external/wpa_supplicant_8" name="platform/external/wpa_supplicant_8" groups="pdk" />
-  <project path="external/xdelta3" name="platform/external/xdelta3" />
   <project path="external/xmlwriter" name="platform/external/xmlwriter" />
   <project path="external/xmp_toolkit" name="platform/external/xmp_toolkit" />
   <project path="external/yaffs2" name="platform/external/yaffs2" groups="pdk" />