KT-11870 "Replace with Elvis" refactoring doesn't change the variable type from T? to T

#KT-11870 Fixed

idea/testData/intentions/ifNullToElvis/ExplicitValType.kt

@@ -0,0 +1,8 @@
+// WITH_RUNTIME
+fun foo(): String? = null
+
+fun bar() {
+    val v: String? = foo()
+    <caret>if (v == null) throw Exception()
+    v.length
+}

idea/testData/intentions/ifNullToElvis/ExplicitValType.kt.after

@@ -0,0 +1,7 @@
+// WITH_RUNTIME
+fun foo(): String? = null
+
+fun bar() {
+    val v: String = foo() ?: throw Exception()
+    v.length
+}

idea/testData/intentions/ifNullToElvis/ExplicitVarType.kt

@@ -0,0 +1,9 @@
+// WITH_RUNTIME
+
+fun foo(): String? = null
+
+fun bar() {
+    var v: String? = foo()
+    <caret>if (v == null) throw Exception()
+    v = null
+}

idea/testData/intentions/ifNullToElvis/ExplicitVarType.kt.after

@@ -0,0 +1,8 @@
+// WITH_RUNTIME
+
+fun foo(): String? = null
+
+fun bar() {
+    var v: String? = foo() ?: throw Exception()
+    v = null
+}