ApnSettingsActivity shows the ActionBar

- Use the Theme.Settings.NoActionBar
- Update test cases

Fixes: 331308440
Test: atest com.android.settings.UtilsTest SettingsActivityTest
Change-Id: Ica93e765690707654ae651261ac8d236ed8e1d58
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index 923f5ae..194d017 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -152,7 +152,7 @@
             android:name=".SettingsApplication"
             android:label="@string/settings_label"
             android:icon="@drawable/ic_launcher_settings"
-            android:theme="@style/Theme.Settings"
+            android:theme="@style/Theme.Settings.NoActionBar"
             android:hardwareAccelerated="true"
             android:requiredForAllUsers="true"
             android:supportsRtl="true"