Use TelephonyManager API to check if device is voice capable.

Bug: 146076829
Test: make
Change-Id: I28b708a5838054ec1baa0a086e5e2f6ccc9c0614
diff --git a/src/com/android/settings/CryptKeeper.java b/src/com/android/settings/CryptKeeper.java
index 05054b4..df912db 100644
--- a/src/com/android/settings/CryptKeeper.java
+++ b/src/com/android/settings/CryptKeeper.java
@@ -964,7 +964,7 @@
     }
 
     private boolean isEmergencyCallCapable() {
-        return getResources().getBoolean(com.android.internal.R.bool.config_voice_capable);
+        return getTelephonyManager().isVoiceCapable();
     }
 
     private void takeEmergencyCallAction() {