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
diff --git a/src/com/android/launcher3/ExtendedEditText.java b/src/com/android/launcher3/ExtendedEditText.java
index 8ec5c18..8ff030e 100644
--- a/src/com/android/launcher3/ExtendedEditText.java
+++ b/src/com/android/launcher3/ExtendedEditText.java
@@ -101,8 +101,14 @@
     }
 
     public void hideKeyboard() {
+        hideKeyboard(/* clearFocus= */ true);
+    }
+
+    public void hideKeyboard(boolean clearFocus) {
         ActivityContext.lookupContext(getContext()).hideKeyboard();
-        clearFocus();
+        if (clearFocus) {
+            clearFocus();
+        }
     }
 
     protected void onKeyboardShown() {