TIF: Do not build input list for background user

Building input list for background user leads to unnecessary connection
request to hardware input and that causes incomplete service state.

Bug: 27407198
Change-Id: Id8d5d5001394781edd2dafe8681c674855332ae3

services/core/java/com/android/server/tv/TvInputManagerService.java

@@ -161,8 +161,10 @@ public final class TvInputManagerService extends SystemService {
         PackageMonitor monitor = new PackageMonitor() {
             private void buildTvInputList(String[] packages) {
                 synchronized (mLock) {
-                    buildTvInputListLocked(getChangingUserId(), packages);
-                    buildTvContentRatingSystemListLocked(getChangingUserId());
+                    if (mCurrentUserId == getChangingUserId()) {
+                        buildTvInputListLocked(mCurrentUserId, packages);
+                        buildTvContentRatingSystemListLocked(mCurrentUserId);
+                    }
                 }
             }