Step1: Create a status bar class like below
public class StatusBarView extends View
{
    private int mStatusBarHeight;
    public StatusBarView(Context context)
    {
        this(context, null);
    }
    public StatusBarView(Context context, AttributeSet attrs)
    {
        super(context, attrs);
        if( Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP){
            setSystemUiVisibility(SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);
        }
    }
    @Override
    public WindowInsets onApplyWindowInsets(WindowInsets insets)
    {
        if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP){
            mStatusBarHeight = insets.getSystemWindowInsetTop();
            return insets.consumeSystemWindowInsets();
        }
        return insets;
    }
    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
    {
        setMeasuredDimension(MeasureSpec.getSize(widthMeasureSpec),mStatusBarHeight);
    }
}
Step2: create a drawable gradient like below
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">
    <gradient
        android:type="linear"
        android:angle="135"
        android:endColor="#F34D80"
        android:startColor="#FF5858"/><!--android:centerColor="#C12389"-->
</shape>
Step3: create a layout like below
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="vertical">
    <YOURPACKAGENAME.StatusBarView
        android:id="@+id/status_bar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@drawable/toolbar_bg_gradient"/>
    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:background="@drawable/toolbar_bg_gradient"
        android:elevation="0dp"
        android:minHeight="?attr/actionBarSize"
        app:contentInsetStartWithNavigation="0dp"
        app:popupTheme="@style/AppTheme.PopupOverlay"
        app:subtitleTextColor="@android:color/white"
        app:theme="@style/AppTheme.AppBarOverlay"
        app:titleTextColor="@android:color/white" />
</LinearLayout>
Step4: create a style for activity
<style name="AppTheme.NoActionBarMain" parent="Base.Theme.AppCompat.Light">
        <item name="windowActionBar">false</item>
        <item name="android:windowDisablePreview">true</item>
        <item name="windowNoTitle">true</item>
        <item name="colorPrimary">@color/colorPrimary</item>
        <item name="android:windowContentOverlay">@null</item>
        <item name="android:windowEnableSplitTouch">false</item>
        <item name="android:splitMotionEvents">false</item>
        <item name="android:windowDrawsSystemBarBackgrounds" tools:targetApi="lollipop">true</item>
        <item name="android:statusBarColor" tools:targetApi="lollipop">@android:color/transparent</item>
        <item name="android:colorForeground">@color/foreground_material_light</item>
        <item name="windowActionModeOverlay">true</item>
        <item name="actionModeStyle">@style/LywActionMode</item>
    </style>
<style name="LywActionMode" parent="Base.Widget.AppCompat.ActionMode">
        <item name="background">@color/colorPrimary</item>
        <item name="backgroundSplit">@color/colorPrimary</item>
    </style>