[tools] Add retries when trying to discover the device

This is an experimental change that may help mitigate the issue.

TBR=machenbach@chromium.org

No-Try: true
No-Tree-Checks: true
Bug: chromium:893593
Change-Id: Ideb74a83b9937dbe917e8c7c93305d9824b48a93
Reviewed-on: https://chromium-review.googlesource.com/c/1339419
Commit-Queue: Sergiy Byelozyorov <sergiyb@chromium.org>
Reviewed-by: Sergiy Byelozyorov <sergiyb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57556}

tools/testrunner/local/android.py

@@ -50,8 +50,13 @@ class _Driver(object):
     devil_chromium.Initialize()
 
     if not device:
-      # Detect attached device if not specified.
-      devices = adb_wrapper.AdbWrapper.Devices()
+      # Detect attached device if not specified. Retry 3 times with 60 second
+      # sleep in-between.
+      for _ in range(3):
+        devices = adb_wrapper.AdbWrapper.Devices()
+        if devices:
+          break
+        time.sleep(60)
       assert devices, 'No devices detected'
       assert len(devices) == 1, 'Multiple devices detected.'
       device = str(devices[0])