fix lint error

Change-Id: Iba3b09f2eb271c4b9b35b9a4c162698dd24f02ad

Author: alabiaga

samples/user-interface/live-updates/src/main/java/com/example/platform/ui/live_updates/LiveUpdateSample.kt

@@ -3,6 +3,8 @@ package com.example.platform.ui.live_updates
 import android.annotation.SuppressLint
 import android.app.NotificationManager
 import android.content.Context
+import android.os.Build
+import androidx.annotation.RequiresApi
 import androidx.compose.foundation.layout.Box
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Spacer
@@ -30,6 +32,7 @@ import com.google.accompanist.permissions.rememberPermissionState
 import com.google.accompanist.permissions.shouldShowRationale
 import kotlinx.coroutines.launch
 
+@RequiresApi(Build.VERSION_CODES.O)
 @Composable
 fun LiveUpdateSample() {
     val notificationManager =