Android Kotlin - AdView adSize: val cannot be reassigned

MobileAds.initialize(this) { }

val adViewBottom = AdView(this)
adViewBottom.adSize = AdSize.BANNER

This worked before I updated the library, now I get

val cannot be reassigned

on

adViewBottom.adSize

changing `val` to `var` doesn't solve it

Admob 21.0.0 changed the way to set ad size directly.
You can use the `setAdSize` method.

```kotlin
MobileAds.initialize(this) { }

val adViewBottom = AdView(this)
adViewBottom.setAdSize(AdSize.BANNER)
// adViewBottom.setAdSize(AdSize.FULL_BANNER)
// adViewBottom.setAdSize(... Anchored adaptive banner size ...)
```

If you updated adMob dependency to`implementation 'com.google.android.gms:play-services-ads:21.1.0'` And your intention is to use Anchored adaptive banner, most probably you will get that error. Here is the solution that works for me.

MobileAds.initialize(this) {}

adView = AdView(this)//instance of adView
//get width of a device from window manager
val display = windowManager.defaultDisplay
val outMetrics = DisplayMetrics()
display.getMetrics(outMetrics)

val density = outMetrics.density

var adWidthPixels = adContainerView.width.toFloat()
if (adWidthPixels == 0f) {
adWidthPixels = outMetrics.widthPixels.toFloat()
}

val adWidth = (adWidthPixels / density).toInt()

adView.setAdSize(AdSize.getCurrentOrientationAnchoredAdaptiveBannerAdSize(this, adWidth))

Set in this way

adViewBottom.setAdSize(AdSize.BANNER)