Revert "Support two pane design in the Settings app."

This reverts commit a12a0d1eb234e4841a6633d4614e91a28f5c1517.

Reason for revert:  See a build error in git_sc-v2-dev-plus-aosp/aosp_crosshatch-userdebug

Bug: 198722766
Change-Id: Ibf812bf92595f57409e3c6d9cda6a1dfa4a8c72c
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index d8bbe8f..c88639f 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -108,9 +108,7 @@
     <uses-permission android:name="android.permission.READ_DREAM_SUPPRESSION" />
     <uses-permission android:name="android.permission.MANAGE_APP_HIBERNATION" />
 
-    <application
-            android:name=".SettingsApplication"
-            android:label="@string/settings_label"
+    <application android:label="@string/settings_label"
             android:icon="@drawable/ic_launcher_settings"
             android:theme="@style/Theme.Settings"
             android:hardwareAccelerated="true"