fix: set idle timeout for bazel to 240 seconds (#653)

Author: alexander-fenster

synthtool/gcp/gapic_bazel.py

@@ -171,7 +171,7 @@ def _generate_code(
 
         bazel_run_args = [
             "bazel",
-            "--max_idle_secs=60",
+            "--max_idle_secs=240",
             "build",
             bazel_target,
         ]