Not working on api lower than 21

Your sample app does not run in device with api lower than 21.
It may be because of vector drawable.
I produce this error on genymotion api 19

> E/AndroidRuntime( 2575): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.hanks.demo/com.hanks.demo.PasscodeActivity}: android.view.InflateException: Binary XML file line #2: Error inflating class com.hanks.passcodeview.PasscodeView
E/AndroidRuntime( 2575): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2184)
E/AndroidRuntime( 2575): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2233)
E/AndroidRuntime( 2575): at android.app.ActivityThread.access$800(ActivityThread.java:135)
E/AndroidRuntime( 2575): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1196)
E/AndroidRuntime( 2575): at android.os.Handler.dispatchMessage(Handler.java:102)
E/AndroidRuntime( 2575): at android.os.Looper.loop(Looper.java:136)
E/AndroidRuntime( 2575): at android.app.ActivityThread.main(ActivityThread.java:5001)
E/AndroidRuntime( 2575): at java.lang.reflect.Method.invokeNative(Native Method)
E/AndroidRuntime( 2575): at java.lang.reflect.Method.invoke(Method.java:515)
E/AndroidRuntime( 2575): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785)
E/AndroidRuntime( 2575): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)
E/AndroidRuntime( 2575): at dalvik.system.NativeStart.main(Native Method)
E/AndroidRuntime( 2575): Caused by: android.view.InflateException: Binary XML file line #2: Error inflating class com.hanks.passcodeview.PasscodeView
E/AndroidRuntime( 2575): at android.view.LayoutInflater.createView(LayoutInflater.java:620)
E/AndroidRuntime( 2575): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:696)
E/AndroidRuntime( 2575): at android.view.LayoutInflater.inflate(LayoutInflater.java:469)
E/AndroidRuntime( 2575): at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
E/AndroidRuntime( 2575): at android.view.LayoutInflater.inflate(LayoutInflater.java:353)
E/AndroidRuntime( 2575): at android.support.v7.app.AppCompatDelegateImplV9.setContentView(AppCompatDelegateImplV9.java:287)
E/AndroidRuntime( 2575): at android.support.v7.app.AppCompatActivity.setContentView(AppCompatActivity.java:139)
E/AndroidRuntime( 2575): at com.hanks.demo.PasscodeActivity.onCreate(PasscodeActivity.java:20)
E/AndroidRuntime( 2575): at android.app.Activity.performCreate(Activity.java:5231)
E/AndroidRuntime( 2575): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087)
E/AndroidRuntime( 2575): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2148)
E/AndroidRuntime( 2575): ... 11 more
E/AndroidRuntime( 2575): Caused by: java.lang.reflect.InvocationTargetException
E/AndroidRuntime( 2575): at java.lang.reflect.Constructor.constructNative(Native Method)
E/AndroidRuntime( 2575): at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
E/AndroidRuntime( 2575): at android.view.LayoutInflater.createView(LayoutInflater.java:594)
E/AndroidRuntime( 2575): ... 21 more
E/AndroidRuntime( 2575): Caused by: android.view.InflateException: Binary XML file line #70: Error inflating class
E/AndroidRuntime( 2575): at android.view.LayoutInflater.createView(LayoutInflater.java:620)
E/AndroidRuntime( 2575): at com.android.internal.policy.impl.PhoneLayoutInflater.onCreateView(PhoneLayoutInflater.java:56)
E/AndroidRuntime( 2575): at android.view.LayoutInflater.onCreateView(LayoutInflater.java:669)
E/AndroidRuntime( 2575): at android.view.LayoutInflater.createViewFromTag(LayoutInflater.java:694)
E/AndroidRuntime( 2575): at android.view.LayoutInflater.rInflate(LayoutInflater.java:755)
E/AndroidRuntime( 2575): at android.view.LayoutInflater.inflate(LayoutInflater.java:492)
E/AndroidRuntime( 2575): at android.view.LayoutInflater.inflate(LayoutInflater.java:397)
E/AndroidRuntime( 2575): at android.view.LayoutInflater.inflate(LayoutInflater.java:353)
E/AndroidRuntime( 2575): at android.view.View.inflate(View.java:17465)
E/AndroidRuntime( 2575): at com.hanks.passcodeview.PasscodeView.(PasscodeView.java:66)
E/AndroidRuntime( 2575): ... 24 more
E/AndroidRuntime( 2575): Caused by: java.lang.reflect.InvocationTargetException
E/AndroidRuntime( 2575): at java.lang.reflect.Constructor.constructNative(Native Method)
E/AndroidRuntime( 2575): at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
E/AndroidRuntime( 2575): at android.view.LayoutInflater.createView(LayoutInflater.java:594)
E/AndroidRuntime( 2575): ... 33 more
E/AndroidRuntime( 2575): Caused by: android.content.res.Resources$NotFoundException: File res/drawable/lock_bg_white.xml from drawable resource ID #0x7f020063
E/AndroidRuntime( 2575): at android.content.res.Resources.loadDrawable(Resources.java:2096)
E/AndroidRuntime( 2575): at android.content.res.TypedArray.getDrawable(TypedArray.java:602)
E/AndroidRuntime( 2575): at android.view.View.(View.java:3554)
E/AndroidRuntime( 2575): at android.view.View.(View.java:3484)
E/AndroidRuntime( 2575): at android.view.ViewGroup.(ViewGroup.java:464)
E/AndroidRuntime( 2575): at android.widget.RelativeLayout.(RelativeLayout.java:236)
E/AndroidRuntime( 2575): ... 36 more
E/AndroidRuntime( 2575): Caused by: org.xmlpull.v1.XmlPullParserException: Binary XML file line #2: invalid drawable tag vector
E/AndroidRuntime( 2575): at android.graphics.drawable.Drawable.createFromXmlInner(Drawable.java:933)
E/AndroidRuntime( 2575): at android.graphics.drawable.Drawabl