[Android] Fix misc minor provisioning issues.

build/android/pylib/content_settings.py

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 
 class ContentSettings(dict):
 
   """A dict interface to interact with device content settings.
 
   System properties are key/value pairs as exposed by adb shell content.
@@ skipping 32 matching lines @@
         'content query --uri content://%s' % self._table, as_root=True):
       fields = row.split(', ')
       key = None
       value = None
       for field in fields:
         k, _, v = field.partition('=')
         if k == 'name':
           key = v
         elif k == 'value':
           value = v
-      assert key, value
+      if not key:
+        continue
+      if not value:
+        value = ''
       yield key, value
 
   def __getitem__(self, key):
     return self._device.RunShellCommand(
         'content query --uri content://%s --where "name=\'%s\'" '
         '--projection value' % (self._table, key), as_root=True).strip()
 
   def __setitem__(self, key, value):
     if key in self:
       self._device.RunShellCommand(
@@ skipping 11 matching lines @@
               self._GetTypeBinding(value), value),
           as_root=True)
 
   def __delitem__(self, key):
     self._device.RunShellCommand(
         'content delete --uri content://%s '
         '--bind name:%s:%s' % (
             self._table,
             self._GetTypeBinding(key), key),
         as_root=True)