always overwrite README.md

Partial commit for third_party/*, see #7430.

Signed-off-by: iirina <elenairina@google.com>

third_party/java/java_tools/update_java_tools.sh

diff --git a/third_party/java/java_tools/update_java_tools.sh b/third_party/java/java_tools/update_java_tools.sh
index 7665ab5..779f4c8 100755
--- a/third_party/java/java_tools/update_java_tools.sh
+++ b/third_party/java/java_tools/update_java_tools.sh
@@ -118,7 +118,7 @@
 if [[ ${#updated_tools[@]} -gt 0 ]]; then
   bazel_version=$(bazel version | grep "Build label" | cut -d " " -f 3)
   git_head=$(git rev-parse HEAD)
-  cat >>third_party/java/java_tools/README.md <<EOL
+  cat >third_party/java/java_tools/README.md <<EOL
 
 The following tools were built with bazel $bazel_version at commit $git_head
 by running: