Increase wait time for unmounting runtimes

Change-Id: Ic6de62feeb6029ef74a3da553b29c374271306cf
Reviewed-on: https://flutter-review.googlesource.com/c/recipes/+/52441
Commit-Queue: Victoria Ashworth <vashworth@google.com>
Reviewed-by: Yusuf Mohsinally <mohsinally@google.com>
diff --git a/recipe_modules/osx_sdk/api.py b/recipe_modules/osx_sdk/api.py
index 79cd50e..43d73fa 100644
--- a/recipe_modules/osx_sdk/api.py
+++ b/recipe_modules/osx_sdk/api.py
@@ -466,13 +466,13 @@
             step_text=simulator_cleanup_stderr,
         )
 
-      # Wait until runtimes are unmounted
+      # Wait up to ~5 minutes until runtimes are unmounted.
       self.m.retry.basic_wrap(
           self._is_runtimes_unmounted,
           step_name='Wait for runtimes to unmount',
-          sleep=3.0,
+          sleep=5.0,
           backoff_factor=2,
-          max_attempts=3
+          max_attempts=7
       )
 
       if not self._runtime_versions: