Use mktemp when creating temporary files.

Before this change, the Java binary shell stub created temporary files in the
directory containing the binary, but that fails when the binary is stored in a
read-only file system or the directory is write protected.

Fixes issue #6289

Closes #6471.

PiperOrigin-RevId: 218314425

src/main/java/com/google/devtools/build/lib/bazel/rules/java/java_stub_template.txt

@@ -305,9 +305,8 @@ function create_and_run_classpath_jar() {
  done
  unset IFS
 
- RAND_ID=$(cat /dev/urandom | head -c 128 | md5func)
  # Create manifest file
- MANIFEST_FILE="${self}-${RAND_ID}.jar_manifest"
+ MANIFEST_FILE="$(mktemp XXXXXXXX.jar_manifest)"
 
  (
  echo "Manifest-Version: 1.0"
@@ -325,7 +324,7 @@ function create_and_run_classpath_jar() {
  ) >$MANIFEST_FILE
 
  # Create classpath JAR file
- MANIFEST_JAR_FILE="${self}-${RAND_ID}-classpath.jar"
+ MANIFEST_JAR_FILE="$(mktemp XXXXXXXX-classpath.jar)"
  if is_windows; then
  MANIFEST_JAR_FILE="$(cygpath --windows "$MANIFEST_JAR_FILE")"
  MANIFEST_FILE="$(cygpath --windows "$MANIFEST_FILE")"