remove external/checkpolicy and external/libsepol

These projects are no longer used and have been replaced by
external/selinux.
Change-Id: If6dc1e9261f397d801ba2376ab60c5dc5b5d86e4

default.xml

@@ -73,7 +73,6 @@
   <project path="external/bzip2" name="platform/external/bzip2" groups="pdk" />
   <project path="external/cblas" name="platform/external/cblas" />
   <project path="external/ceres-solver" name="platform/external/ceres-solver" groups="pdk-cw-fs" />
-  <project path="external/checkpolicy" name="platform/external/checkpolicy" groups="pdk" />
   <project path="external/chromium-libpac" name="platform/external/chromium-libpac" />
   <project path="external/chromium-trace" name="platform/external/chromium-trace" groups="pdk" />
   <project path="external/chromium_org" name="platform/external/chromium_org" />
@@ -189,7 +188,6 @@
   <project path="external/libpng" name="platform/external/libpng" groups="pdk" />
   <project path="external/libseccomp-helper" name="platform/external/libseccomp-helper" groups="pdk-cw-fs" />
   <project path="external/libselinux" name="platform/external/libselinux" groups="pdk" />
-  <project path="external/libsepol" name="platform/external/libsepol" groups="pdk" />
   <project path="external/libssh2" name="platform/external/libssh2" groups="pdk-cw-fs" />
   <project path="external/libunwind" name="platform/external/libunwind" groups="pdk" />
   <project path="external/libusb" name="platform/external/libusb" groups="pdk-cw-fs" />