tools: cpplint: add option to fetch specific version

This makes it easier to update in small steps for testing.

Bug: None
Test: `./tools/cpplint.py-update --rev 1.5.5` fetches version 1.5.5
Change-Id: Ib277ecdbfaa3d03d5c2c19ff079a0326be73e30d
Reviewed-on: https://android-review.googlesource.com/c/platform/tools/repohooks/+/3494610
Performance: CrystalBall Performance Presubmit <android-crystalball-presubmit-eng@google.com>
Autosubmit: Mike Frysinger <vapier@google.com>
Reviewed-by: Leandro Lovisolo <lovisolo@google.com>
Lint: Lint 🤖 <ayeaye-gerrit@google.com>
Presubmit-Verified: Treehugger Robot <android-test-infra-workplan-finisher@system.gserviceaccount.com>
Open-Source-Licensing: Lint 🤖 <ayeaye-gerrit@google.com>

tools/cpplint.py-update

diff --git a/tools/cpplint.py-update b/tools/cpplint.py-update
index 6414381..40d047a 100755
--- a/tools/cpplint.py-update
+++ b/tools/cpplint.py-update
@@ -25,8 +25,7 @@
 
 # Since this is manually run by repohooks developers, we can safely require more
 # recent versions of Python.
-assert (sys.version_info.major, sys.version_info.minor) >= (3, 9), (
-    f"Python 3.9 or newer is required; found {sys.version}")
+assert sys.version_info >= (3, 9), f"Python 3.9+ required; found {sys.version}"
 
 
 THIS_FILE = Path(__file__).resolve()
@@ -77,7 +76,7 @@
     if lines[0].endswith(b"python"):
         lines[0] += b"3"
     lines.insert(1, b"# pylint: skip-file")
-    return b"\n".join(lines)
+    return b"\n".join(lines).rstrip() + b"\n"
 
 
 def update_script(data: str) -> None:
@@ -89,6 +88,10 @@
 def get_parser() -> argparse.ArgumentParser:
     """Return a command line parser."""
     parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument(
+        "--rev",
+        help="What git commit or ref to fetch (default: latest)",
+    )
     return parser
 
 
@@ -98,7 +101,9 @@
 
     ret = 0
 
-    commit = find_latest_tag()
+    commit = opts.rev
+    if not commit:
+        commit = find_latest_tag()
     data = download(commit)
     data = munge_content(data)
     update_script(data)