releasetools: Add dict-like setter to BuildInfo.

BuildInfo already has dict-like getters. This CL adds the matching
setter method to keep it backward compatible with device-specific
scripts that expect a dict.

It also adds items() method that allows iterating the items.

Bug: 111087332
Test: python -m unittest test_ota_from_target_files.BuildInfoTest
Test: Generate an incremental OTA that sets info_dict in device-specific
      releasetools script.
Change-Id: Idd033f98a9186740f9da1a300d4c2bdddd9c1345
diff --git a/tools/releasetools/test_ota_from_target_files.py b/tools/releasetools/test_ota_from_target_files.py
index e472363..7c34b7e 100644
--- a/tools/releasetools/test_ota_from_target_files.py
+++ b/tools/releasetools/test_ota_from_target_files.py
@@ -190,6 +190,16 @@
     self.assertRaises(KeyError,
                       lambda: target_info['build.prop']['ro.build.foo'])
 
+  def test___setitem__(self):
+    target_info = BuildInfo(copy.deepcopy(self.TEST_INFO_DICT), None)
+    self.assertEqual('value1', target_info['property1'])
+    target_info['property1'] = 'value2'
+    self.assertEqual('value2', target_info['property1'])
+
+    self.assertEqual('build-foo', target_info['build.prop']['ro.build.foo'])
+    target_info['build.prop']['ro.build.foo'] = 'build-bar'
+    self.assertEqual('build-bar', target_info['build.prop']['ro.build.foo'])
+
   def test_get(self):
     target_info = BuildInfo(self.TEST_INFO_DICT, None)
     self.assertEqual('value1', target_info.get('property1'))
@@ -209,6 +219,12 @@
     self.assertRaises(KeyError,
                       lambda: target_info.get('build.prop')['ro.build.foo'])
 
+  def test_items(self):
+    target_info = BuildInfo(self.TEST_INFO_DICT, None)
+    items = target_info.items()
+    self.assertIn(('property1', 'value1'), items)
+    self.assertIn(('property2', 4096), items)
+
   def test_GetBuildProp(self):
     target_info = BuildInfo(self.TEST_INFO_DICT, None)
     self.assertEqual('build-foo', target_info.GetBuildProp('ro.build.foo'))