J2K: Insert !! for expression only if NotNull expected (not for Default nullability)

j2k/src/org/jetbrains/kotlin/j2k/CodeConverter.kt

@@ -96,7 +96,7 @@ class CodeConverter(
 
         var convertedExpression = convertExpression(expression)
 
-        if (convertedExpression.isNullable && expectedNullability != null && !expectedNullability.isNullable(settings)) {
+        if (convertedExpression.isNullable && expectedNullability != null && expectedNullability == Nullability.NotNull) {
             convertedExpression = BangBangExpression.surroundIfNullable(convertedExpression)
         }
 

j2k/testData/fileOrElement/nullability/notNullCast.kt

@@ -1,3 +1,5 @@
+// ERROR: Type mismatch: inferred type is Passenger.PassChild? but Passenger.PassChild was expected
+// ERROR: Type mismatch: inferred type is Passenger.PassChild? but Passenger.PassChild was expected
 class Passenger {
     open class PassParent
 
@@ -16,9 +18,9 @@ class Passenger {
         val pass = provideNullable(1)
         if (1 == 2) {
             assert(pass != null)
-            accept2((pass as PassChild?)!!)
+            accept2(pass as PassChild?)
         }
-        accept2((pass as PassChild?)!!)
+        accept2(pass as PassChild?)
     }
 
     fun accept1(p: PassChild) {

j2k/testData/fileOrElement/nullability/nullableField.kt

@@ -1,3 +1,7 @@
+// ERROR: Type mismatch: inferred type is String? but String was expected
+// ERROR: Type mismatch: inferred type is Int? but Int was expected
+// ERROR: Type inference failed. Please try to specify type arguments explicitly.
+// ERROR: Using 'remove(Int): T' is an error. Use removeAt(index) instead.
 package test
 
 import java.util.ArrayList
@@ -16,7 +20,7 @@ class Test {
     }
 
     fun test2() {
-        foo2(myProp!!)
+        foo2(myProp)
     }
 
     fun test3() {
@@ -39,7 +43,7 @@ class Test {
 
     fun test7() {
         val list = ArrayList<Int>()
-        list.remove(myIntProp!!)
+        list.remove(myIntProp)
     }
 
     fun foo1(s: String) {