Move InputMethodSytemProperty to server from client.

Moving InputMethodSystemProperty from android.view.inputmethod to
com.android.server.inputmethod so that it can be accessed only from
the system_server.

Change-Id: I41707a4e5dfe824cbe9e873ec598762d36c64c09
Fix: 137203823
Test: Build and flash
diff --git a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
index c37ced5..dac8968 100644
--- a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
+++ b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
@@ -225,7 +225,6 @@
 import android.view.RemoteAnimationAdapter;
 import android.view.RemoteAnimationDefinition;
 import android.view.WindowManager;
-import android.view.inputmethod.InputMethodSystemProperty;
 
 import com.android.internal.R;
 import com.android.internal.annotations.VisibleForTesting;
@@ -262,6 +261,7 @@
 import com.android.server.am.UserState;
 import com.android.server.appop.AppOpsService;
 import com.android.server.firewall.IntentFirewall;
+import com.android.server.inputmethod.InputMethodSystemProperty;
 import com.android.server.pm.UserManagerService;
 import com.android.server.policy.PermissionPolicyInternal;
 import com.android.server.uri.UriGrantsManagerInternal;