Fix SubFilterViewModelTest mock and posttypes manifest merger conflict

Revert savedTag mock to use property access (no-arg getLabel) matching
production code, and remove allowBackup/usesCleartextTraffic from
posttypes library manifest to fix manifest merger conflict.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: nbradbury

WordPress/src/test/java/org/wordpress/android/ui/reader/subfilter/SubFilterViewModelTest.kt

@@ -91,7 +91,7 @@ class SubFilterViewModelTest : BaseUnitTest() {
 
     @Before
     fun setUp() {
-        whenever(savedTag.getLabel(anyOrNull())).thenReturn("tag-label")
+        whenever(savedTag.label).thenReturn("tag-label")
 
         viewModel = SubFilterViewModel(
             testDispatcher(),

libs/posttypes/src/main/AndroidManifest.xml

@@ -6,8 +6,6 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools">
     <application
-        android:allowBackup="false"
-        android:usesCleartextTraffic="false"
         tools:ignore="UnusedAttribute">
         <activity
             android:name="org.wordpress.android.posttypes.CptPostTypesActivity"