Track external/zstd

Our forks allows support for additional features such as:
- Additional zstd cmdline tools
- zstd compression support for rsync

Change-Id: I8009d5a7076c6dcfc68763d419c018f56eae0d08
diff --git a/default.xml b/default.xml
index a63a162..7ecab80 100644
--- a/default.xml
+++ b/default.xml
@@ -715,7 +715,7 @@
   <project path="external/yapf" name="platform/external/yapf" groups="vts,projectarch,pdk" remote="aosp" />
   <project path="external/zlib" name="platform/external/zlib" groups="pdk" remote="aosp" />
   <project path="external/zopfli" name="platform/external/zopfli" groups="pdk" remote="aosp" />
-  <project path="external/zstd" name="platform/external/zstd" groups="pdk" remote="aosp" />
+  <project path="external/zstd" name="LineageOS/android_external_zstd" />
   <project path="external/zucchini" name="platform/external/zucchini" groups="pdk" remote="aosp" />
   <project path="external/zxing" name="platform/external/zxing" groups="pdk" remote="aosp" />
   <project path="frameworks/av" name="LineageOS/android_frameworks_av" groups="pdk" />