Fix flag check for preserve settings feature

getApplicationContext() returns null when calling to get Context object
to pass to FeatureFlagUtils.isEnabled(). Replace with getBaseContext()

Test: Verify the context is not null through logs
Change-Id: I0c27c5bc09e3fc84abeafb0a4ead3357cacc3d2a

packages/SettingsProvider/src/com/android/providers/settings/SettingsBackupAgent.java

@@ -626,7 +626,7 @@ public class SettingsBackupAgent extends BackupAgentHelper {
      * Get names of the settings for which the current value should be preserved during restore.
      */
     private Set<String> getSettingsToPreserveInRestore(Uri settingsUri) {
-        if (!FeatureFlagUtils.isEnabled(getApplicationContext(),
+        if (!FeatureFlagUtils.isEnabled(getBaseContext(),
                 FeatureFlagUtils.SETTINGS_DO_NOT_RESTORE_PRESERVED)) {
             return Collections.emptySet();
         }