Do nothing if hideSoftInput is called from not focused client.

IMMS#hideSoftInput calls IMMS#setImeWindowVisibilityStatusHiddenLocked
if it is called from not focused client.  However this function changes
IMS visibility state and also changes the back key indicator wrongly.
IMMS should just ignore IMMS#hideSoftInput from not-focused client.

As a preparation to fix b/20764441, this CL partially reverts
Ife3a8733b1a1bf43b195ecf4b8c5082b6538d0a0 but shouldn't have any
user-visible UX regressions.

Bug: 20764441

Change-Id: I60963f1474457ff37cca85e262460dca8105acff

services/core/java/com/android/server/InputMethodManagerService.java

@@ -2038,11 +2038,9 @@ public class InputMethodManagerService extends IInputMethodManager.Stub
                         if (!mIWindowManager.inputMethodClientHasFocus(client)) {
                             if (DEBUG) Slog.w(TAG, "Ignoring hideSoftInput of uid "
                                     + uid + ": " + client);
-                            setImeWindowVisibilityStatusHiddenLocked();
                             return false;
                         }
                     } catch (RemoteException e) {
-                        setImeWindowVisibilityStatusHiddenLocked();
                         return false;
                     }
                 }