Revert "Change FxNimbus initialization sequence (#25089)"

This reverts commit 51ba7ab463.

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

@@ -72,7 +72,6 @@ import org.mozilla.fenix.components.toolbar.ToolbarPosition
 import org.mozilla.fenix.ext.isCustomEngine
 import org.mozilla.fenix.ext.isKnownSearchDomain
 import org.mozilla.fenix.ext.settings
-import org.mozilla.fenix.nimbus.FxNimbus
 import org.mozilla.fenix.perf.MarkersActivityLifecycleCallbacks
 import org.mozilla.fenix.perf.ProfilerMarkerFactProcessor
 import org.mozilla.fenix.perf.StartupTimeline
@@ -394,8 +393,7 @@ open class FenixApplication : LocaleAwareApplication(), Provider {
     private fun setupMegazord(): Deferred<Unit> {
         // Note: Megazord.init() must be called as soon as possible ...
         Megazord.init()
-        // Give the generated FxNimbus a closure to lazily get the Nimbus object
-        FxNimbus.initialize { components.analytics.experiments }
+
         return GlobalScope.async(Dispatchers.IO) {
             // ... but RustHttpConfig.setClient() and RustLog.enable() can be called later.
             RustHttpConfig.setClient(lazy { components.core.client })

app/src/main/java/org/mozilla/fenix/components/Analytics.kt

@@ -124,7 +124,9 @@ class Analytics(
     }
 
     val experiments: NimbusApi by lazyMonitored {
-        createNimbus(context, BuildConfig.NIMBUS_ENDPOINT)
+        createNimbus(context, BuildConfig.NIMBUS_ENDPOINT).also { api ->
+            FxNimbus.api = api
+        }
     }
 
     val messagingStorage by lazyMonitored {

app/src/main/java/org/mozilla/fenix/experiments/NimbusSetup.kt

@@ -13,26 +13,11 @@ import mozilla.components.service.nimbus.NimbusAppInfo
 import mozilla.components.service.nimbus.NimbusDisabled
 import mozilla.components.service.nimbus.NimbusServerSettings
 import mozilla.components.support.base.log.logger.Logger
-import org.mozilla.experiments.nimbus.NimbusInterface
-import org.mozilla.experiments.nimbus.internal.EnrolledExperiment
 import org.mozilla.experiments.nimbus.internal.NimbusException
 import org.mozilla.fenix.BuildConfig
 import org.mozilla.fenix.R
 import org.mozilla.fenix.ext.components
 import org.mozilla.fenix.ext.settings
-import org.mozilla.fenix.nimbus.FxNimbus
-
-/**
- * Fenix specific observer of Nimbus events.
- *
- * The generated code `FxNimbus` provides a cache which should be invalidated
- * when the experiments recipes are updated.
- */
-private val observer = object : NimbusInterface.Observer {
-    override fun onUpdatesApplied(updated: List<EnrolledExperiment>) {
-        FxNimbus.invalidateCachedValues()
-    }
-}
 
 @Suppress("TooGenericExceptionCaught")
 fun createNimbus(context: Context, url: String?): NimbusApi {
@@ -84,10 +69,6 @@ fun createNimbus(context: Context, url: String?): NimbusApi {
             )
         )
         Nimbus(context, appInfo, serverSettings, errorReporter).apply {
-            // We register our own internal observer for housekeeping the Nimbus SDK and
-            // generated code.
-            register(observer)
-
             // This performs the minimal amount of work required to load branch and enrolment data
             // into memory. If `getExperimentBranch` is called from another thread between here
             // and the next nimbus disk write (setting `globalUserParticipation` or

app/src/test/java/org/mozilla/fenix/settings/SettingsFragmentTest.kt

@@ -11,6 +11,7 @@ import io.mockk.mockk
 import io.mockk.mockkObject
 import kotlinx.coroutines.test.advanceUntilIdle
 import mozilla.components.concept.fetch.Client
+import mozilla.components.service.nimbus.NimbusDisabled
 import mozilla.components.support.test.robolectric.testContext
 import mozilla.components.support.test.rule.MainCoroutineRule
 import mozilla.components.support.test.rule.runTestOnMain
@@ -29,6 +30,7 @@ import org.mozilla.fenix.ext.components
 import org.mozilla.fenix.ext.getPreferenceKey
 import org.mozilla.fenix.ext.settings
 import org.mozilla.fenix.helpers.FenixRobolectricTestRunner
+import org.mozilla.fenix.nimbus.FxNimbus
 import org.mozilla.fenix.utils.Settings
 import org.robolectric.Robolectric
 import java.io.IOException
@@ -54,6 +56,8 @@ class SettingsFragmentTest {
         mockkObject(Config)
         every { Config.channel } returns ReleaseChannel.Nightly
 
+        FxNimbus.api = NimbusDisabled(testContext)
+
         val activity = Robolectric.buildActivity(FragmentActivity::class.java).create().get()
         activity.supportFragmentManager.beginTransaction()
             .add(settingsFragment, "test")