Set preview/experimental compiler flags instead of using annotations

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

@@ -57,7 +57,6 @@ import eu.kanade.tachiyomi.util.view.showBar
 import eu.kanade.tachiyomi.util.view.snack
 import eu.kanade.tachiyomi.widget.SimpleAnimationListener
 import eu.kanade.tachiyomi.widget.SimpleSeekBarListener
-import kotlinx.coroutines.FlowPreview
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.drop
 import kotlinx.coroutines.flow.launchIn
@@ -653,7 +652,6 @@ class ReaderActivity : BaseRxActivity<ReaderActivityBinding, ReaderPresenter>()
     /**
      * Class that handles the user preferences of the reader.
      */
-    @FlowPreview
     private inner class ReaderConfig {
 
         /**
@@ -774,7 +772,6 @@ class ReaderActivity : BaseRxActivity<ReaderActivityBinding, ReaderPresenter>()
         /**
          * Sets the custom brightness overlay according to [enabled].
          */
-        @FlowPreview
         private fun setCustomBrightness(enabled: Boolean) {
             if (enabled) {
                 preferences.customBrightnessValue().asFlow()
@@ -789,7 +786,6 @@ class ReaderActivity : BaseRxActivity<ReaderActivityBinding, ReaderPresenter>()
         /**
          * Sets the color filter overlay according to [enabled].
          */
-        @FlowPreview
         private fun setColorFilter(enabled: Boolean) {
             if (enabled) {
                 preferences.colorFilterValue().asFlow()