Add capability to identify phone accounts that are emergency only.

Bug: 24756957
Change-Id: Id26eaa7f6632674f7122b4cd658cbe2bf9b04594
diff --git a/telecomm/java/android/telecom/PhoneAccount.java b/telecomm/java/android/telecom/PhoneAccount.java
index cdb0bf2..b64043c 100644
--- a/telecomm/java/android/telecom/PhoneAccount.java
+++ b/telecomm/java/android/telecom/PhoneAccount.java
@@ -121,6 +121,14 @@
     public static final int CAPABILITY_CALL_SUBJECT = 0x40;
 
     /**
+     * Flag indicating that this {@code PhoneAccount} should only be used for emergency calls.
+     * <p>
+     * See {@link #getCapabilities}
+     * @hide
+     */
+    public static final int CAPABILITY_EMERGENCY_CALLS_ONLY = 0x80;
+
+    /**
      * URI scheme for telephone number URIs.
      */
     public static final String SCHEME_TEL = "tel";