Revert "For #8460: Prevent multiple back navigation clicks."

This reverts commit b030d3ac9f.

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

@@ -16,7 +16,6 @@ import androidx.annotation.VisibleForTesting
 import androidx.annotation.VisibleForTesting.PROTECTED
 import androidx.appcompat.app.ActionBar
 import androidx.appcompat.widget.Toolbar
-import androidx.core.view.children
 import androidx.lifecycle.lifecycleScope
 import androidx.navigation.NavDestination
 import androidx.navigation.NavDirections
@@ -24,7 +23,6 @@ import androidx.navigation.fragment.NavHostFragment
 import androidx.navigation.ui.AppBarConfiguration
 import androidx.navigation.ui.NavigationUI
 import kotlinx.android.synthetic.main.activity_home.navigationToolbarStub
-import kotlinx.android.synthetic.main.navigation_toolbar.navigationToolbar
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.launch
 import mozilla.components.browser.search.SearchEngine
@@ -70,8 +68,6 @@ import org.mozilla.fenix.settings.logins.SavedLoginsFragmentDirections
 import org.mozilla.fenix.theme.DefaultThemeManager
 import org.mozilla.fenix.theme.ThemeManager
 import org.mozilla.fenix.utils.BrowsersCache
-import java.util.Timer
-import kotlin.concurrent.schedule
 
 @SuppressWarnings("TooManyFunctions", "LargeClass")
 open class HomeActivity : LocaleAwareAppCompatActivity() {
@@ -229,11 +225,6 @@ open class HomeActivity : LocaleAwareAppCompatActivity() {
                 return
             }
         }
-        // Temporary disable back button in action bar to prevent multiple navigation on fast consecutive clicks.
-        // See #8460
-        navigationToolbar.setChildrenClickable(false, 0)
-        navigationToolbar.setChildrenClickable(true, THROTTLE_TIME_MS)
-
         super.onBackPressed()
     }
 
@@ -415,14 +406,6 @@ open class HomeActivity : LocaleAwareAppCompatActivity() {
         navHost.navController.navigate(action)
     }
 
-    private fun Toolbar.setChildrenClickable(boolean: Boolean, delayTime: Long) {
-        Timer().schedule(delayTime) {
-            this@setChildrenClickable.children.forEach {
-                it.isClickable = boolean
-            }
-        }
-    }
-
     companion object {
         const val OPEN_TO_BROWSER = "open_to_browser"
         const val OPEN_TO_BROWSER_AND_LOAD = "open_to_browser_and_load"
@@ -430,6 +413,5 @@ open class HomeActivity : LocaleAwareAppCompatActivity() {
         const val PRIVATE_BROWSING_MODE = "private_browsing_mode"
         const val EXTRA_DELETE_PRIVATE_TABS = "notification_delete_and_open"
         const val EXTRA_OPENED_FROM_NOTIFICATION = "notification_open"
-        const val THROTTLE_TIME_MS = 500L
     }
 }