Use getCallStateForSubscription to replace deprecated getCallState

getCallState was deprecated, use getCallStateForSubscription to get the call state.

https://developer.android.com/reference/android/telephony/TelephonyManager#getCallState%28%29
diff --git a/src/main/java/com/google/android/mobly/snippet/bundled/TelephonySnippet.java b/src/main/java/com/google/android/mobly/snippet/bundled/TelephonySnippet.java
index 21c5d1e..1463915 100644
--- a/src/main/java/com/google/android/mobly/snippet/bundled/TelephonySnippet.java
+++ b/src/main/java/com/google/android/mobly/snippet/bundled/TelephonySnippet.java
@@ -47,7 +47,7 @@
                     "Gets the call state for the default subscription. Call state values are"
                             + "0: IDLE, 1: RINGING, 2: OFFHOOK")
     public int getTelephonyCallState() {
-        return mTelephonyManager.getCallState();
+        return mTelephonyManager.getCallStateForSubscription();
     }
 
     @Rpc(