Bump cros VM sanity test timeout to 10min and reduce retry count by 1.

If chrome crashes on startup, the test itself will fail gracefully
after ~7 min. Bumping timeout let's us hit that reliably, and lets the
test do some cleanup. (Instead of killing it early.)

R=jbudorick

Change-Id: I9c23198e3267b3a438b9a41daadb4ba70e20de4d
Reviewed-on: https://chromium-review.googlesource.com/c/1262799Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Cr-Commit-Position: refs/heads/master@{#597159}

build/chromeos/run_vm_test.py

@@ -317,9 +317,9 @@ class BrowserSanityTest(RemoteTest):
   def __init__(self, args, unknown_args):
     super(BrowserSanityTest, self).__init__(args, unknown_args)
 
-    # 5 min should be enough time for the sanity test to pass.
-    self._retries = 2
-    self._timeout = 300
+    # 10 min should be enough time for the sanity test to pass.
+    self._retries = 1
+    self._timeout = 600
 
   @property
   def suite_name(self):