Use some more KTX and Compat stuff (#3933)

* Use more KTX extensions

* Update Android Studio

* Use more Compat classes

app/src/main/java/eu/kanade/tachiyomi/data/download/DownloadService.kt

@@ -7,9 +7,9 @@ import android.content.Intent
 import android.net.ConnectivityManager
 import android.net.NetworkInfo.State.CONNECTED
 import android.net.NetworkInfo.State.DISCONNECTED
-import android.os.Build
 import android.os.IBinder
 import android.os.PowerManager
+import androidx.core.content.ContextCompat
 import com.github.pwittchen.reactivenetwork.library.Connectivity
 import com.github.pwittchen.reactivenetwork.library.ReactiveNetwork
 import com.jakewharton.rxrelay.BehaviorRelay
@@ -47,11 +47,7 @@ class DownloadService : Service() {
          */
         fun start(context: Context) {
             val intent = Intent(context, DownloadService::class.java)
-            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
-                context.startService(intent)
-            } else {
-                context.startForegroundService(intent)
-            }
+            ContextCompat.startForegroundService(context, intent)
         }
 
         /**