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"),