For #6521 - Remove auto sigin onboarding card (#16315)

With the Fennec -> Fenix migration complete there is no other Mozilla
application that would serve as a custom account provider hence the automatic
signin would not be possible.
Make this more obvious by commenting out the code that would trigger an
onboarding banner for it but keep the code in the app for when #15694 would add
to Fenix the ability to serve as a custom account provider.

app/src/main/java/org/mozilla/fenix/home/Mode.kt

@@ -59,12 +59,10 @@ class CurrentMode(
         if (account != null) {
             Mode.Onboarding(OnboardingState.SignedIn)
         } else {
-            val availableAccounts = accountManager.shareableAccounts(context)
-            if (availableAccounts.isEmpty()) {
-                Mode.Onboarding(OnboardingState.SignedOutNoAutoSignIn)
-            } else {
-                Mode.Onboarding(OnboardingState.SignedOutCanAutoSignIn(availableAccounts[0]))
-            }
+            Mode.Onboarding(OnboardingState.SignedOutNoAutoSignIn)
+            // The following other state is effectively disabled - #6521
+            // Code still exists in app for when it will be used again - #15694
+            // Mode.Onboarding(OnboardingState.SignedOutCanAutoSignIn(accountManager.shareableAccounts(context)[0]))
         }
     }
 

app/src/test/java/org/mozilla/fenix/home/ModeTest.kt

@@ -10,7 +10,6 @@ import io.mockk.mockk
 import io.mockk.spyk
 import io.mockk.verify
 import mozilla.components.service.fxa.manager.FxaAccountManager
-import mozilla.components.service.fxa.sharing.ShareableAccount
 import org.junit.Assert.assertEquals
 import org.junit.Before
 import org.junit.Test
@@ -79,18 +78,19 @@ class ModeTest {
         assertEquals(Mode.Onboarding(OnboardingState.SignedOutNoAutoSignIn), currentMode.getCurrentMode())
     }
 
-    @Test
-    fun `get current onboarding mode when can auto sign in`() {
-        val shareableAccount: ShareableAccount = mockk()
-        every { onboarding.userHasBeenOnboarded() } returns false
-        every { accountManager.authenticatedAccount() } returns null
-        every { accountManager.shareableAccounts(context) } returns listOf(shareableAccount)
-
-        assertEquals(
-            Mode.Onboarding(OnboardingState.SignedOutCanAutoSignIn(shareableAccount)),
-            currentMode.getCurrentMode()
-        )
-    }
+    // Temporarily disabled. See #6521
+    // @Test
+    // fun `get current onboarding mode when can auto sign in`() {
+    //     val shareableAccount: ShareableAccount = mockk()
+    //     every { onboarding.userHasBeenOnboarded() } returns false
+    //     every { accountManager.authenticatedAccount() } returns null
+    //     every { accountManager.shareableAccounts(context) } returns listOf(shareableAccount)
+    //
+    //     assertEquals(
+    //         Mode.Onboarding(OnboardingState.SignedOutCanAutoSignIn(shareableAccount)),
+    //         currentMode.getCurrentMode()
+    //     )
+    // }
 
     @Test
     fun `emit mode change`() {