@Sunita answer is correct, but if you are using API 21 the status bar color will be light if you set so and status bar text color will also be light, and on 23+ it will work fine. On new apis with themes and night themes (dark mode) I would do it by adding the v23/styles.xml and set the status bar background and text color there:
<item name="android:statusBarColor">@color/lightColor</item>
<item name="android:windowLightStatusBar">true</item>
And in the night/styles.xml:
<item name="android:statusBarColor" tools:targetApi="l">@color/darkColor</item>
<item name="android:windowLightStatusBar" tools:targetApi="m">false</item>
The default styles.xml wouldn't contain any of this code, or just this, but remember to not set it to light:
<item name="android:statusBarColor">?attr/colorPrimaryVariant</item>
This way we are setting the light background (and text color) for status bar but only for devices with api 23+. On devices <23 background will not be changed, as I think this is something that we dont want knowing that the text color will stay white.
The dark theme was added on API 29, so we don't have to be afraid of dark theme on api 21 ;)
The drawback of this however is that we are adding another file that we will need to remember to manage.