Pack libfec.so into otatools.zip.

delta_generator now has a dependency on libfec.so [1], for generating
A/B incrementals.

[1] https://android-review.googlesource.com/c/platform/system/update_engine/+/854154

Bug: 122280472
Test: `m -j otatools-package` with aosp_marlin-userdebug. Check that
      `otatools.zip` contains libfec.so.
Change-Id: Ia6642bb2c7ccb0f89ad3079bdf65e4dbffee13f5
diff --git a/core/Makefile b/core/Makefile
index 179cf29..c5dbe24 100644
--- a/core/Makefile
+++ b/core/Makefile
@@ -3282,7 +3282,8 @@
   $(HOST_LIBRARY_PATH)/libpcre2$(HOST_SHLIB_SUFFIX) \
   $(HOST_LIBRARY_PATH)/libbrotli$(HOST_SHLIB_SUFFIX) \
   $(HOST_LIBRARY_PATH)/liblp$(HOST_SHLIB_SUFFIX) \
-  $(HOST_LIBRARY_PATH)/libext4_utils$(HOST_SHLIB_SUFFIX)
+  $(HOST_LIBRARY_PATH)/libext4_utils$(HOST_SHLIB_SUFFIX) \
+  $(HOST_LIBRARY_PATH)/libfec$(HOST_SHLIB_SUFFIX)
 
 
 .PHONY: otatools