Check Various IMS interfaces before returning cached value

If the ImsService goes down, the stale binder interfaces
to the old service still get returned by ImsManager. This
change triggers the ImsManager to fetch the binder interfaces
again if the cached one is dead.

Bug: 62723694
Test: Manual, test procedure outlined in bug
Change-Id: I64c1c668602d88663220a50c2e45ae4f970ac302
diff --git a/src/java/com/android/ims/ImsEcbm.java b/src/java/com/android/ims/ImsEcbm.java
index 9fa9598..53549bf 100644
--- a/src/java/com/android/ims/ImsEcbm.java
+++ b/src/java/com/android/ims/ImsEcbm.java
@@ -78,6 +78,10 @@
         }
     }
 
+    public boolean isBinderAlive() {
+        return miEcbm.asBinder().isBinderAlive();
+    }
+
     /**
      * Adapter class for {@link IImsEcbmListener}.
      */