Fix focus navigation of All Apps when using external keyboard.

- All apps icons do not show the focus rectangle when focused as mIconFocusListener is null in BaseAllAppsAdapter when onCreateViewHolder is called.
- All apps recyclerview does not scroll down when focus goes from top to bottom of list, as AllAppsToastUiDelegate calls hideKeyboard which clears focus.
- Focus goes behind AllApps into hotseat, so update hotseat setDescendantFocusability.

Flag: NONE
Fix: 296844600
Test: TaplKeyboardFocusTest
Change-Id: I65f6fbb6f4df0be4b4ff922dda267d27da16effe

src/com/android/launcher3/allapps/BaseAllAppsAdapter.java

@@ -27,7 +27,6 @@ import android.widget.TextView;
 import androidx.recyclerview.widget.RecyclerView;
 
 import com.android.launcher3.BubbleTextView;
-import com.android.launcher3.Flags;
 import com.android.launcher3.R;
 import com.android.launcher3.allapps.search.SearchAdapterProvider;
 import com.android.launcher3.config.FeatureFlags;
@@ -213,6 +212,7 @@ public abstract class BaseAllAppsAdapter<T extends Context & ActivityContext> ex
                 BubbleTextView icon = (BubbleTextView) holder.itemView;
                 icon.reset();
                 icon.applyFromApplicationInfo(adapterItem.itemInfo);
+                icon.setOnFocusChangeListener(mIconFocusListener);
                 break;
             }
             case VIEW_TYPE_EMPTY_SEARCH: {