[iOS][test runner] Run `xcrun simctl` after xcode-select.

This is a work around to eliminate the bad impact of mixed usage of
Xcode 11 & Xcode 12 on one machine.

Bug: 1115022
Change-Id: I11c97719a79951bc1c7073362c5661ac3cb03ab1
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2363687
Commit-Queue: Zhaoyang Li <zhaoyangli@chromium.org>
Reviewed-by: Justin Cohen <justincohen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#805148}

ios/build/bots/scripts/xcode_util.py

@@ -20,9 +20,14 @@ def select(xcode_app_path):
       '-s',
       xcode_app_path,
   ]
-  LOGGER.debug("Selecting XCode with command: %s" % cmd)
-
+  LOGGER.debug('Selecting XCode with command: %s and "xcrun simctl list".' % cmd)
   output = subprocess.check_output(cmd, stderr=subprocess.STDOUT)
+
+  # This is to avoid issues caused by mixed usage of different Xcode versions on
+  # one machine.
+  xcrun_simctl_cmd = ['xcrun', 'simctl', 'list']
+  output += subprocess.check_output(xcrun_simctl_cmd, stderr=subprocess.STDOUT)
+
   return output