cros lint: check the indentation level of section arguments

Sometimes the indentation of things like "Args:" is incorrect.
Add a linter check for it and fix up all the existing errors.

BUG=chromium:485005
TEST=`cros lint` on all files pass, and catches some bad cases

Change-Id: I79ea60d1e07c40d9283284bdaebfcda5af4e6246
Reviewed-on: https://chromium-review.googlesource.com/269642
Trybot-Ready: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Prathmesh Prabhu <pprabhu@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/upload_prebuilts.py b/scripts/upload_prebuilts.py
index 85c8fd4..8744274 100644
--- a/scripts/upload_prebuilts.py
+++ b/scripts/upload_prebuilts.py
@@ -263,12 +263,12 @@
 def GetBoardOverlay(build_path, target):
   """Get the path to the board variant.
 
-   Args:
-     build_path: The path to the root of the build directory
-     target: The target board as a BuildTarget object.
+  Args:
+    build_path: The path to the root of the build directory
+    target: The target board as a BuildTarget object.
 
-   Returns:
-     The last overlay configured for the given board as a string.
+  Returns:
+    The last overlay configured for the given board as a string.
   """
   board = target.board_variant
   overlays = portage_util.FindOverlays(constants.BOTH_OVERLAYS, board,