Revert "For #17447: add intentional delay to cold start up in debug and nightly."

This reverts commit 093470a8b3. This
intentional regression was only intended to be temporary so now we're
removing it.

app/src/main/java/org/mozilla/fenix/FeatureFlags.kt

@@ -34,13 +34,6 @@ object FeatureFlags {
     // users are still experiencing crashes.
     const val nimbusExperiments = false
 
-    /**
-     * Enables an intentional regression to validate perftest alerting. See
-     * https://github.com/mozilla-mobile/fenix/issues/17447 for details. This
-     * is expected to be removed within several days.
-     */
-    val intentionalRegressionToValidatePerfTestAlerting = Config.channel.isNightlyOrDebug
-
     /**
      * Enables the new MediaSession API.
      */

app/src/main/java/org/mozilla/fenix/FenixApplication.kt

@@ -119,13 +119,6 @@ open class FenixApplication : LocaleAwareApplication(), Provider {
 
     @CallSuper
     open fun setupInMainProcessOnly() {
-        // See feature flags kdoc for details.
-        if (FeatureFlags.intentionalRegressionToValidatePerfTestAlerting) {
-            logger.info("Intentional thread sleep. See #17447")
-            @Suppress("MagicNumber") // it's fine for a quick patch.
-            Thread.sleep(100)
-        }
-
         run {
             // Attention: Do not invoke any code from a-s in this scope.
             val megazordSetup = setupMegazord()