Register remote transitions on activity start

Was only registering once, but launcher can stop/start
its activity (eg when changing gesture modes), so we
need to try and re-register every time

Bug: 200213691
Test: atest CloseAppHomeButtonTest
      change gesture mode and observe functional animations
Change-Id: I29f1eb647c2168d753e37f57657906979c5518be

quickstep/src/com/android/launcher3/BaseQuickstepLauncher.java

@@ -353,6 +353,7 @@ public abstract class BaseQuickstepLauncher extends Launcher
 
         mAppTransitionManager = new QuickstepTransitionManager(this);
         mAppTransitionManager.registerRemoteAnimations();
+        mAppTransitionManager.registerRemoteTransitions();
 
         internalBindToTIS();
     }