fixed PY-7089 Insert type assertion: leads to syntactically incorrect code when invoked for one-line function

python/testData/intentions/afterDocStub.py

@@ -1,9 +1,9 @@
 def foo(a, b):
-  """
+    """
   
-  :param a: 
-  :param b: 
-  :return:
-  """
-  if True:
-    return
+    :param a:
+    :param b:
+    :return:
+    """
+    if True:
+        return

python/testData/intentions/beforeDocStub.py

@@ -1,3 +1,3 @@
 def fo<caret>o(a, b):
-  if True:
-    return
+    if True:
+        return