Fix call to ImsManager#getInstance

Previous CL had passed in the subId to ImsManager#getInstance instead of
phoneId. This is incorrect and causes the later call to
ImsManager#setRttEnabled to be a no-op. Fix this by correctly passing in
phoneId.

Fixes: 139710080
Test: manual
Change-Id: Ica8c6a0a9634611a82c208d59040dd7a3c95b3fc
diff --git a/src/com/android/phone/settings/AccessibilitySettingsFragment.java b/src/com/android/phone/settings/AccessibilitySettingsFragment.java
index b074f20..73f5de9 100644
--- a/src/com/android/phone/settings/AccessibilitySettingsFragment.java
+++ b/src/com/android/phone/settings/AccessibilitySettingsFragment.java
@@ -166,7 +166,8 @@
             for (int subId : SubscriptionController.getInstance().getActiveSubIdList(true)) {
                 if (!configManager.getConfigForSubId(subId).getBoolean(
                         CarrierConfigManager.KEY_IGNORE_RTT_MODE_SETTING_BOOL, false)) {
-                    ImsManager imsManager = ImsManager.getInstance(getContext(), subId);
+                    int phoneId = SubscriptionController.getInstance().getPhoneId(subId);
+                    ImsManager imsManager = ImsManager.getInstance(getContext(), phoneId);
                     imsManager.setRttEnabled(mButtonRtt.isChecked());
                 }
             }