Ensure external calls do not go through call blocking code.

Note: This is already submit in google3.

Bug: 27458894
Change-Id: I45a7ac7d4e94722fd52c2f83be073f1e90d7b66c
diff --git a/InCallUI/src/com/android/incallui/InCallPresenter.java b/InCallUI/src/com/android/incallui/InCallPresenter.java
index 38507ee..c3ca6de 100644
--- a/InCallUI/src/com/android/incallui/InCallPresenter.java
+++ b/InCallUI/src/com/android/incallui/InCallPresenter.java
@@ -534,6 +534,9 @@
             Log.i(this, "Not attempting to block incoming call due to recent emergency call");
             return false;
         }
+        if (call.getDetails().hasProperty(CallSdkCompat.Details.PROPERTY_IS_EXTERNAL_CALL)) {
+            return false;
+        }
 
         return true;
     }