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/WorkspaceStateTransitionAnimation.java

@@ -49,6 +49,7 @@ import static com.android.launcher3.states.StateAnimationConfig.SKIP_SCRIM;
 import android.animation.ValueAnimator;
 import android.util.FloatProperty;
 import android.view.View;
+import android.view.ViewGroup;
 import android.view.animation.Interpolator;
 
 import com.android.launcher3.LauncherState.PageAlphaProvider;
@@ -164,6 +165,8 @@ public class WorkspaceStateTransitionAnimation {
                 state.hasFlag(FLAG_HOTSEAT_INACCESSIBLE)
                         ? View.IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS
                         : View.IMPORTANT_FOR_ACCESSIBILITY_AUTO);
+        hotseat.setDescendantFocusability(state.hasFlag(FLAG_HOTSEAT_INACCESSIBLE)
+                ? ViewGroup.FOCUS_BLOCK_DESCENDANTS : ViewGroup.FOCUS_BEFORE_DESCENDANTS);
 
         Interpolator translationInterpolator =
                 config.getInterpolator(ANIM_WORKSPACE_TRANSLATE, ZOOM_OUT);