Added tests with class/function used in Java

idea/testData/inspections/unusedSymbol/function/usedInJava.java

@@ -0,0 +1,5 @@
+class RandomJavaClass {
+    void g() {
+        foo.FooPackage.usedInJava();
+    }
+}

idea/testData/inspections/unusedSymbol/function/usedInJava.kt

@@ -0,0 +1,4 @@
+package foo
+
+fun usedInJava() {
+}