Show shapes for nav buttons in debug view

At the moment we show BACK, HOME and RECENT_APPS when using the
navigation buttons; those buttons have geometric shapes (triangle,
circle and square) assigned to them that have a Unicode
representation that we can use instead, similar to other characters
like arrows and Enter.

Bug: 326242357
Test: Flashed on device
Change-Id: I37883b6ba67118781ee9e6edb97d2f1ac5e93f89
diff --git a/services/core/java/com/android/server/input/debug/FocusEventDebugView.java b/services/core/java/com/android/server/input/debug/FocusEventDebugView.java
index 3ffd2e1..b30f5ec 100644
--- a/services/core/java/com/android/server/input/debug/FocusEventDebugView.java
+++ b/services/core/java/com/android/server/input/debug/FocusEventDebugView.java
@@ -313,7 +313,7 @@
             case KeyEvent.KEYCODE_FORWARD_DEL:
                 return "\u2326";
             case KeyEvent.KEYCODE_ESCAPE:
-                return "ESC";
+                return "esc";
             case KeyEvent.KEYCODE_DPAD_UP:
                 return "\u2191";
             case KeyEvent.KEYCODE_DPAD_DOWN:
@@ -330,6 +330,14 @@
                 return "\u2198";
             case KeyEvent.KEYCODE_DPAD_DOWN_LEFT:
                 return "\u2199";
+            case KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE:
+                return "\u23ef";
+            case KeyEvent.KEYCODE_HOME:
+                return "\u25ef";
+            case KeyEvent.KEYCODE_BACK:
+                return "\u25c1";
+            case KeyEvent.KEYCODE_RECENT_APPS:
+                return "\u25a1";
             default:
                 break;
         }