custom_snackbar.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
        xmlns:android="http://schemas.android.com/apk/res/android"
        xmlns:tools="http://schemas.android.com/tools"
        android:id="@+id/snackbar_relativelayout"
        android:layout_width="match_parent"
        android:layout_height="20dp"
        android:alpha="0.6"
        android:layout_gravity="center_horizontal"
        android:background="@android:color/black">

    <TextView
            android:id="@+id/snackbar_text"
            android:layout_width="wrap_content"
            android:layout_height="20dp"
            android:gravity="center"
            android:layout_centerInParent="true"
            tools:text="No connection"
            android:textAppearance="@style/Base.TextAppearance.AppCompat.Small"
            android:textColor="@android:color/white"/>


</RelativeLayout>

CustomSnackbar.kt

//..
import com.google.android.material.snackbar.BaseTransientBottomBar

class CustomSnackbar private constructor(
    parent: ViewGroup, content: View,
    callback: com.google.android.material.snackbar.ContentViewCallback
) : BaseTransientBottomBar<CustomSnackbar>(parent, content, callback) {

    fun setText(text: CharSequence): CustomSnackbar {
        val textView = getView().findViewById<View>(R.id.snackbar_text) as TextView
        textView.text = text
        return this
    }

    /**
     * content view inflation animation
     */
    private class CustomContentViewCallback(private val content: View) :
        com.google.android.material.snackbar.ContentViewCallback {

        override fun animateContentIn(delay: Int, duration: Int) {
        }

        override fun animateContentOut(delay: Int, duration: Int) {
//            ObjectAnimator.ofFloat(content, View.SCALE_Y, 1f, 0f).setDuration(1000).start()
        }
    }

    companion object {
        fun make(parent: ViewGroup, duration: Int): CustomSnackbar {
            val inflater = LayoutInflater.from(parent.context)
            val content = inflater.inflate(R.layout.custom_snackbar, parent, false)
            val viewCallback = CustomContentViewCallback(content)

            return CustomSnackbar(parent, content, viewCallback).run {
                getView().setPadding(0, 0, 0, 0)
                this.duration = duration
                this
            }
        }
    }
}