Revert "Migrate to atomicfu and fix a atomic usage"

Reason for revert: Don't use atomicfu, use platform atomic impl to
benefit from VarHandler backend
This reverts commit a0a215400e.

app/build.gradle.kts

@@ -192,7 +192,6 @@ dependencies {
     // https://coil-kt.github.io/coil/changelog/
     implementation("io.coil-kt:coil-compose:2.2.2")
 
-    implementation("org.jetbrains.kotlinx:atomicfu:0.20.0")
     implementation("org.jetbrains.kotlinx:kotlinx-coroutines-android:1.6.4")
     implementation("org.jetbrains.kotlinx:kotlinx-serialization-cbor:1.5.0-RC")
     implementation("org.jsoup:jsoup:1.15.4")

app/src/main/java/eu/kanade/tachiyomi/ui/reader/ReaderActivity.kt

@@ -85,6 +85,7 @@ import eu.kanade.tachiyomi.ui.reader.setting.ReadingModeType
 import eu.kanade.tachiyomi.ui.reader.viewer.BaseViewer
 import eu.kanade.tachiyomi.ui.reader.viewer.pager.R2LPagerViewer
 import eu.kanade.tachiyomi.util.lang.launchIO
+import eu.kanade.tachiyomi.util.lang.launchUI
 import eu.kanade.tachiyomi.util.lang.withUIContext
 import eu.kanade.tachiyomi.util.preference.toggle
 import eu.kanade.tachiyomi.util.system.applySystemAnimatorScale
@@ -94,7 +95,6 @@ import eu.kanade.tachiyomi.util.view.copy
 import eu.kanade.tachiyomi.util.view.popupMenu
 import eu.kanade.tachiyomi.util.view.setTooltip
 import eu.kanade.tachiyomi.widget.listener.SimpleAnimationListener
-import kotlinx.atomicfu.atomic
 import kotlinx.coroutines.FlowPreview
 import kotlinx.coroutines.currentCoroutineContext
 import kotlinx.coroutines.ensureActive
@@ -109,6 +109,7 @@ import java.io.FileInputStream
 import java.io.IOException
 import java.io.InputStream
 import java.io.OutputStream
+import java.util.concurrent.atomic.AtomicReference
 import kotlin.coroutines.Continuation
 import kotlin.coroutines.resume
 import kotlin.math.abs
@@ -211,7 +212,7 @@ class ReaderActivity : EhActivity() {
                     Toast.makeText(this, R.string.error_reading_failed, Toast.LENGTH_SHORT).show()
                 }
 
-                val continuation = atomic<StringResumeable?>(null)
+                val continuation: AtomicReference<Continuation<String>?> = AtomicReference(null)
                 mGalleryProvider = ArchivePageLoader(this, mUri!!,
                     flow {
                         if (!dialogShown) {
@@ -224,7 +225,7 @@ class ReaderActivity : EhActivity() {
                                         if (passwd.isEmpty())
                                             builder.setError(getString(R.string.passwd_cannot_be_empty))
                                         else {
-                                            continuation.getAndSet(null)?.resume(passwd)
+                                            continuation.get()?.resume(passwd)
                                         }
                                     }
                                     setOnCancelListener {
@@ -236,7 +237,7 @@ class ReaderActivity : EhActivity() {
                         while (true) {
                             currentCoroutineContext().ensureActive()
                             val r = suspendCancellableCoroutine {
-                                continuation.value = it
+                                continuation.set(it)
                                 it.invokeOnCancellation { dialog.dismiss() }
                             }
                             emit(r)
@@ -1147,5 +1148,3 @@ class ReaderActivity : EhActivity() {
         }
     }
 }
-
-typealias StringResumeable = Continuation<String>