Fix synchronization in updateImeTargetWindow

Use lock before accessing Window map and calling
DC.updateImeControlTarget().

Change-Id: I363e3a96fc6041df9b25c649de6bda0a70d40857
Fix: 149491593
Bug: 111084606
Test: atest CtsInputMethodTestCases

services/core/java/com/android/server/wm/WindowManagerService.java

@@ -7317,9 +7317,11 @@ public class WindowManagerService extends IWindowManager.Stub
                 Slog.w(TAG_WM, "updateInputMethodTargetWindow: imeToken=" + imeToken
                         + " imeTargetWindowToken=" + imeTargetWindowToken);
             }
-            final WindowState imeTarget = mWindowMap.get(imeTargetWindowToken);
-            if (imeTarget != null) {
-                imeTarget.getDisplayContent().updateImeControlTarget(imeTarget);
+            synchronized (mGlobalLock) {
+                final WindowState imeTarget = mWindowMap.get(imeTargetWindowToken);
+                if (imeTarget != null) {
+                    imeTarget.getDisplayContent().updateImeControlTarget(imeTarget);
+                }
             }
         }