scripts: deploy_chrome: kill ash after remounting r/w

The common device APIs will remount without killing, so let's align
the deploy_chrome in preparation for switching to the common one.

BUG=b:289176310
TEST=CQ passes

Change-Id: I070dce8a989aa223e6f0ff45143d1330916f1d4e
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/chromite/+/4847273
Commit-Queue: Achuith Bhandarkar <achuith@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>
Auto-Submit: Mike Frysinger <vapier@chromium.org>
diff --git a/scripts/deploy_chrome.py b/scripts/deploy_chrome.py
index d42f7d6..37a09f9 100644
--- a/scripts/deploy_chrome.py
+++ b/scripts/deploy_chrome.py
@@ -245,12 +245,12 @@
 
         self.device.Reboot()
 
-        # Now that the machine has been rebooted, we need to kill Chrome again.
-        self._KillAshChromeIfNeeded()
-
         # Make sure the rootfs is writable now.
         self._MountRootfsAsWritable(check=True)
 
+        # Now that the machine has been rebooted, we need to kill Chrome again.
+        self._KillAshChromeIfNeeded()
+
         return True
 
     def _CheckUiJobStarted(self):