Change default rerandomize and showanswer

The defaults used to be rerandomize=always, showanswer=closed. This is
preserved for capa problems being imported from XML. However, for
courses, and for problems created in Studio, the default has been
changed to never/finished, to match the previous defaults used by
Studio.

common/lib/xmodule/xmodule/capa_module.py

@@ -103,7 +103,7 @@ class CapaFields(object):
         help=("Defines when to show the answer to the problem. "
               "A default value can be set in Advanced Settings."),
         scope=Scope.settings,
-        default="closed",
+        default="finished",
         values=[
             {"display_name": "Always", "value": "always"},
             {"display_name": "Answered", "value": "answered"},
@@ -123,7 +123,7 @@ class CapaFields(object):
         help="Defines how often inputs are randomized when a student loads the problem. "
              "This setting only applies to problems that can have randomly generated numeric values. "
              "A default value can be set in Advanced Settings.",
-        default="always",
+        default="never",
         scope=Scope.settings,
         values=[
             {"display_name": "Always", "value": "always"},
@@ -1112,6 +1112,20 @@ class CapaDescriptor(CapaFields, RawDescriptor):
             path[8:],
         ]
 
+    @classmethod
+    def from_xml(cls, xml_data, system, org=None, course=None):
+        """
+        Augment regular translation w/ setting the pre-Studio defaults.
+        """
+        problem = super(CapaDescriptor, cls).from_xml(xml_data, system, org, course)
+        # pylint: disable=W0212
+        if 'showanswer' not in problem._model_data:
+            problem.showanswer = "closed"
+        if 'rerandomize' not in problem._model_data:
+            problem.rerandomize = "always"
+        return problem
+
+
     @property
     def non_editable_metadata_fields(self):
         non_editable_fields = super(CapaDescriptor, self).non_editable_metadata_fields

common/lib/xmodule/xmodule/templates/problem/circuitschematic.yaml

@@ -1,8 +1,6 @@
 ---
 metadata:
     display_name: Circuit Schematic Builder
-    rerandomize: never
-    showanswer: finished
     markdown: !!null
 data: |
       <problem >

common/lib/xmodule/xmodule/templates/problem/forumularesponse.yaml

@@ -1,8 +1,6 @@
 ---
 metadata:
     display_name: Math Expression Input
-    rerandomize: never
-    showanswer: finished
     markdown: !!null
 data: |
   <problem>

common/lib/xmodule/xmodule/templates/problem/imageresponse.yaml

@@ -1,8 +1,6 @@
 ---
 metadata:
     display_name: Image Mapped Input
-    rerandomize: never
-    showanswer: finished
     markdown: !!null
 data: |
   <problem>

common/lib/xmodule/xmodule/templates/problem/multiplechoice.yaml

@@ -1,8 +1,6 @@
 ---
 metadata:
     display_name: Multiple Choice
-    rerandomize: never
-    showanswer: finished
     markdown: |
        A multiple choice problem presents radio buttons for student input. Students can only select a single 
        option presented. Multiple Choice questions have been the subject of many areas of research due to the early 

common/lib/xmodule/xmodule/templates/problem/numericalresponse.yaml

@@ -1,8 +1,6 @@
 ---
 metadata:
     display_name: Numerical Input
-    rerandomize: never
-    showanswer: finished
     markdown: |
        A numerical input problem accepts a line of text input from the
        student, and evaluates the input for correctness based on its

common/lib/xmodule/xmodule/templates/problem/optionresponse.yaml

@@ -1,8 +1,6 @@
 ---
 metadata:
     display_name: Dropdown
-    rerandomize: never
-    showanswer: finished
     markdown: |
         Dropdown problems give a limited set of options for students to respond with, and present those options
         in a format that encourages them to search for a specific answer rather than being immediately presented 

common/lib/xmodule/xmodule/templates/problem/string_response.yaml

@@ -1,8 +1,6 @@
 ---
 metadata:
     display_name: Text Input
-    rerandomize: never
-    showanswer: finished
     markdown: |
         A text input problem accepts a line of text from the 
         student, and evaluates the input for correctness based on an expected 

common/lib/xmodule/xmodule/tests/test_capa_module.py

@@ -636,10 +636,10 @@ class CapaModuleTest(unittest.TestCase):
 
         # Expect that the problem was reset
         module.new_lcp.assert_called_once_with(None)
-        module.choose_new_seed.assert_called_once_with()
 
     def test_reset_problem_closed(self):
-        module = CapaFactory.create()
+        # pre studio default
+        module = CapaFactory.create(rerandomize="always")
 
         # Simulate that the problem is closed
         with patch('xmodule.capa_module.CapaModule.closed') as mock_closed:
@@ -900,13 +900,13 @@ class CapaModuleTest(unittest.TestCase):
         module = CapaFactory.create(done=False)
         self.assertFalse(module.should_show_reset_button())
 
-        # Otherwise, DO show the reset button
-        module = CapaFactory.create(done=True)
+        # pre studio default value, DO show the reset button
+        module = CapaFactory.create(rerandomize="always", done=True)
         self.assertTrue(module.should_show_reset_button())
 
         # If survey question for capa (max_attempts = 0),
         # DO show the reset button
-        module = CapaFactory.create(max_attempts=0, done=True)
+        module = CapaFactory.create(rerandomize="always", max_attempts=0, done=True)
         self.assertTrue(module.should_show_reset_button())
 
     def test_should_show_save_button(self):
@@ -940,8 +940,8 @@ class CapaModuleTest(unittest.TestCase):
         module = CapaFactory.create(max_attempts=None, rerandomize="per_student", done=True)
         self.assertFalse(module.should_show_save_button())
 
-        # Otherwise, DO show the save button
-        module = CapaFactory.create(done=False)
+        # pre-studio default, DO show the save button
+        module = CapaFactory.create(rerandomize="always", done=False)
         self.assertTrue(module.should_show_save_button())
 
         # If we're not randomizing and we have limited attempts,  then we can save