Clean up symbol symlinks for com.android.runtime.

It's not applicable now when we use a prebuilt.

Test: `art/tools/buildbot-build.sh --target` on arm_krait
Bug: 152255951
Change-Id: I2fd128ae22c607bfdc53498f3ed501c95c5c6cf6
diff --git a/tools/buildbot-build.sh b/tools/buildbot-build.sh
index 34c1b4c..134a327 100755
--- a/tools/buildbot-build.sh
+++ b/tools/buildbot-build.sh
@@ -179,13 +179,6 @@
   link_command="mkdir -p $(dirname "$link_name") && ln -sf com.android.art.testing \"$link_name\""
   echo "Executing $link_command"
   eval "$link_command"
-  # Also provide access to symbols of binaries from the Runtime (Bionic) APEX,
-  # e.g. to support debugging in GDB.
-  find "$target_out_unstripped/apex/com.android.runtime/bin" -type f | while read target; do
-    cmd="ln -sf $target $target_out_unstripped/system/bin/$(basename $target)"
-    echo "Executing $cmd"
-    eval "$cmd"
-  done
 
   # Temporary fix for libjavacrypto.so dependencies in libcore and jvmti tests (b/147124225).
   conscrypt_dir="$ANDROID_PRODUCT_OUT/system/apex/com.android.conscrypt"