TunnelManager: disallow remote apps for L

I don't trust old Android versions to have gotten this right.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

ui/src/main/java/com/wireguard/android/activity/SettingsActivity.kt

@@ -82,6 +82,10 @@ class SettingsActivity : ThemeChangeAwareActivity() {
                 darkTheme?.parent?.removePreference(darkTheme)
                 --preferenceScreen.initialExpandedChildrenCount
             }
+            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
+                val remoteApps = preferenceManager.findPreference<Preference>("allow_remote_control_intents")
+                remoteApps?.parent?.removePreference(remoteApps)
+            }
             val wgQuickOnlyPrefs = arrayOf(
                     preferenceManager.findPreference("tools_installer"),
                     preferenceManager.findPreference("restore_on_boot"),

ui/src/main/java/com/wireguard/android/model/TunnelManager.java

@@ -9,6 +9,7 @@ import android.annotation.SuppressLint;
 import android.content.BroadcastReceiver;
 import android.content.Context;
 import android.content.Intent;
+import android.os.Build;
 
 import com.wireguard.android.Application;
 import com.wireguard.android.BR;
@@ -278,7 +279,8 @@ public final class TunnelManager extends BaseObservable {
                 return;
             }
 
-            if (!Application.getSharedPreferences().getBoolean("allow_remote_control_intents", false))
+            if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M ||
+                    !Application.getSharedPreferences().getBoolean("allow_remote_control_intents", false))
                 return;
 
             final State state;