Add failure screenshots and render test images to results detail.

build/android/pylib/instrumentation/instrumentation_test_instance.py

Index: build/android/pylib/instrumentation/instrumentation_test_instance.py
diff --git a/build/android/pylib/instrumentation/instrumentation_test_instance.py b/build/android/pylib/instrumentation/instrumentation_test_instance.py
index 2800b6f6a9b84127c8a6170125944ebaf3dbf183..65fa0c98e6748c9eed01ccb95deaaf8c6da9fd28 100644
--- a/build/android/pylib/instrumentation/instrumentation_test_instance.py
+++ b/build/android/pylib/instrumentation/instrumentation_test_instance.py
@@ -497,6 +497,7 @@ class InstrumentationTestInstance(test_instance.TestInstance):
     self._store_tombstones = False
     self._initializeTombstonesAttributes(args)
 
+    self._should_save_images = None
     self._should_save_logcat = None
     self._initializeLogAttributes(args)
 
@@ -674,6 +675,7 @@ class InstrumentationTestInstance(test_instance.TestInstance):
 
   def _initializeLogAttributes(self, args):
     self._should_save_logcat = bool(args.json_results_file)
+    self._should_save_images = bool(args.json_results_file)
 
   @property
   def additional_apks(self):
@@ -708,6 +710,10 @@ class InstrumentationTestInstance(test_instance.TestInstance):
     return self._flags
 
   @property
+  def should_save_images(self):
+    return self._should_save_images
+
+  @property
   def should_save_logcat(self):
     return self._should_save_logcat