Fix issue #13564072: Back button no longer dismisses IME after voice usage

Calling identity wasn't being cleared in an incoming code path.

Change-Id: Ib32060a91bf81531de049fafde69835b5382a25f
diff --git a/services/core/java/com/android/server/InputMethodManagerService.java b/services/core/java/com/android/server/InputMethodManagerService.java
index 31822e7..5fb6405 100644
--- a/services/core/java/com/android/server/InputMethodManagerService.java
+++ b/services/core/java/com/android/server/InputMethodManagerService.java
@@ -581,7 +581,12 @@
 
         @Override
         public void sessionCreated(IInputMethodSession session) {
-            mParentIMMS.onSessionCreated(mMethod, session, mChannel);
+            long ident = Binder.clearCallingIdentity();
+            try {
+                mParentIMMS.onSessionCreated(mMethod, session, mChannel);
+            } finally {
+                Binder.restoreCallingIdentity(ident);
+            }
         }
     }