Revert "[Settings] Support getSystemService(Class<T>)"

This reverts commit d5ccde31a8.

Reason for revert: failure on test cases

Change-Id: I0a179a6ebb5ef1dec566ce6e8facd5f3b82d7c8a

src/com/android/settings/wifi/dpp/WifiDppUtils.java

@@ -373,8 +373,8 @@ public class WifiDppUtils {
      *                        device security or if lock screen is unlocked
      */
     public static void showLockScreen(Context context, Runnable successRunnable) {
-        final KeyguardManager keyguardManager = context.getSystemService(
-                KeyguardManager.class);
+        final KeyguardManager keyguardManager = (KeyguardManager) context.getSystemService(
+                Context.KEYGUARD_SERVICE);
 
         if (keyguardManager.isKeyguardSecure()) {
             final BiometricPrompt.AuthenticationCallback authenticationCallback =