Fix default icon

Credential entries with or without icons will always have non-null icon reference.
The valid icons will have non-null drawable reference but invalid
ones will have null drawable reference. If the drawable reference is null, then
use the default icon instead of the icon reference that is stored in the
map which won't display anything.

Bug: 299321128
Test: local device testing

Change-Id: Ib20046f5a8e3c66fb546bf6e8dde49388160739e

packages/CredentialManager/src/com/android/credentialmanager/autofill/CredentialAutofillService.kt

@@ -219,9 +219,15 @@ class CredentialAutofillService : AutofillService() {
             val sliceBuilder = InlineSuggestionUi
                     .newContentBuilder(pendingIntent)
                     .setTitle(primaryEntry.userName)
-            val icon: Icon =
-                    entryIconMap[primaryEntry.entryKey + primaryEntry.entrySubkey]
-                            ?: getDefaultIcon()
+            val icon: Icon
+            if (primaryEntry.icon == null) {
+                // The empty entry icon has non-null icon reference but null drawable reference.
+                // If the drawable reference is null, then use the default icon.
+                icon = getDefaultIcon()
+            } else {
+                icon = entryIconMap[primaryEntry.entryKey + primaryEntry.entrySubkey]
+                        ?: getDefaultIcon()
+            }
             sliceBuilder.setStartIcon(icon)
             val inlinePresentation = InlinePresentation(
                     sliceBuilder.build().slice, spec, /* pinned= */ false)