add HelloWorld test smali file into unit-test

brut.apktool/apktool-lib/src/test/resources/brut/apktool/testapp/smali/HelloWorld.smali

@@ -0,0 +1,15 @@
+.class public LHelloWorld;
+
+.super Ljava/lang/Object;
+
+.method public static main([Ljava/lang/String;)V
+    .registers 2
+
+    sget-object v0, Ljava/lang/System;->out:Ljava/io/PrintStream;
+
+    const-string	v1, "Hello World!"
+
+    invoke-virtual {v0, v1}, Ljava/io/PrintStream;->println(Ljava/lang/String;)V
+
+    return-void
+.end method