Prevent NPE in CustomTile

The icon is passed by the TileService, so it could null when retrieving
the drawable. Check for null before doing operations on it.

Test: atest CustomTileTest
Fixes: 140479361
Change-Id: I0ee11806c0047e0e524f5201d369bee51beba451
Merged-In: I0ee11806c0047e0e524f5201d369bee51beba451
(cherry picked from commit cfdd8d4093)

packages/SystemUI/src/com/android/systemui/qs/external/CustomTile.java

@@ -327,6 +327,7 @@ public class CustomTile extends QSTileImpl<State> implements TileChangeListener
 
         final Drawable drawableF = drawable;
         state.iconSupplier = () -> {
+            if (drawableF == null) return null;
             Drawable.ConstantState cs = drawableF.getConstantState();
             if (cs != null) {
                 return new DrawableIcon(cs.newDrawable());

packages/SystemUI/tests/src/com/android/systemui/qs/external/CustomTileTest.kt

@@ -125,4 +125,12 @@ class CustomTileTest : SysuiTestCase() {
         customTile.handleUpdateState(state, null)
         assertFalse(state.value)
     }
+
+    @Test
+    fun testNoCrashOnNullDrawable() {
+        customTile.qsTile.icon = mock(Icon::class.java)
+        `when`(customTile.qsTile.icon.loadDrawable(any(Context::class.java)))
+                .thenReturn(null)
+        customTile.handleUpdateState(customTile.newTileState(), null)
+    }
 }