Skip apply_gerrit rebase when there is a rebase failure

recipe_modules/bot_update/resources/bot_update.py

Index: recipe_modules/bot_update/resources/bot_update.py
diff --git a/recipe_modules/bot_update/resources/bot_update.py b/recipe_modules/bot_update/resources/bot_update.py
index 044f0838f266018a443ba0e1fbad58a19f3998c6..f4a307b25fbef2b9c4016c320cc98cc0d63df010 100755
--- a/recipe_modules/bot_update/resources/bot_update.py
+++ b/recipe_modules/bot_update/resources/bot_update.py
@@ -604,7 +604,12 @@ def apply_gerrit_ref(gerrit_repo, gerrit_ref, root, gerrit_reset,
       try:
         ok = False
         git('checkout', '-b', temp_branch_name, cwd=root)
-        git('rebase', base_rev, cwd=root)
+        try:
+          git('rebase', base_rev, cwd=root)
+        except SubprocessFailed:
+          # Abort the rebase since there were failures.
+          git('rebase', '--abort', cwd=root)
+          raise
 
         # Get off of the temporary branch since it can't be deleted otherwise.
         cur_rev = git('rev-parse', 'HEAD', cwd=root).strip()