Remove FastServiceLoader hack.

FastServiceLoader has been fixed in Kotlin Coroutines 1.3.3, so we no longer
need to disable it.
cf. Kotlin/kotlinx.coroutines#1572

Author: yamasa

sample_app/src/main/java/com/linecorp/lich/sample/MyApplication.kt

@@ -19,18 +19,8 @@ import android.app.Application
 import android.os.StrictMode
 
 class MyApplication : Application() {
-
-    init {
-        // Disable FastServiceLoader.
-        // To avoid StrictMode DiskReadViolation, we use the standard ServiceLoader to load
-        // MainDispatcherFactory.
-        // cf. https://github.com/Kotlin/kotlinx.coroutines/issues/1231
-        System.setProperty("kotlinx.coroutines.fast.service.loader", "false")
-    }
-
     override fun onCreate() {
         super.onCreate()
-
         StrictMode.enableDefaults()
     }
 }