Fix addition of wrong java.lang imports on optimize imports

Add check to star importer, to not import already imported fqNames
 #KT-15273 fixed

idea/ide-common/src/org/jetbrains/kotlin/idea/util/OptimizedImportsBuilder.kt

@@ -155,8 +155,10 @@ class OptimizedImportsBuilder(
             }
             else {
                 descriptors
+                        .asSequence()
                         .filterIsInstance<ClassDescriptor>()
-                        .mapTo(classNamesToCheck) { it.importableFqName!! }
+                        .map { it.importableFqName!! }
+                        .filterTo(classNamesToCheck) { !isImportedByDefault(it) }
 
                 if (!fqNames.all(this::isImportedByDefault)) {
                     importsToGenerate.add(starImportPath)

idea/testData/editor/optimizeImports/jvm/allUnderImports/ClassNameConflictWithinDefaultImports.kt

@@ -0,0 +1,11 @@
+// NAME_COUNT_TO_USE_STAR_IMPORT: 1
+// RUNTIME_WITH_FULL_JDK
+import java.lang.Character.*
+
+/**
+ * [String]
+ */
+fun String.some() {
+    System.out
+    UPPERCASE_LETTER
+}

idea/testData/editor/optimizeImports/jvm/allUnderImports/ClassNameConflictWithinDefaultImports.kt.after

@@ -0,0 +1,11 @@
+// NAME_COUNT_TO_USE_STAR_IMPORT: 1
+// RUNTIME_WITH_FULL_JDK
+import java.lang.Character.UPPERCASE_LETTER
+
+/**
+ * [String]
+ */
+fun String.some() {
+    System.out
+    UPPERCASE_LETTER
+}

idea/tests/org/jetbrains/kotlin/idea/imports/JvmOptimizeImportsTestGenerated.java

@@ -220,6 +220,12 @@ public class JvmOptimizeImportsTestGenerated extends AbstractJvmOptimizeImportsT
                 doTest(fileName);
             }
 
+            @TestMetadata("ClassNameConflictWithinDefaultImports.kt")
+            public void testClassNameConflictWithinDefaultImports() throws Exception {
+                String fileName = KotlinTestUtils.navigationMetadata("idea/testData/editor/optimizeImports/jvm/allUnderImports/ClassNameConflictWithinDefaultImports.kt");
+                doTest(fileName);
+            }
+
             @TestMetadata("NameCountSetting.kt")
             public void testNameCountSetting() throws Exception {
                 String fileName = KotlinTestUtils.navigationMetadata("idea/testData/editor/optimizeImports/jvm/allUnderImports/NameCountSetting.kt");