Move category refresh call into a separeate method.

By default we no longer refresh category with each setTileEnabled.
Instead app will call update after all setTileEnabled are called.

This saves a lot of async task execution when Settings app starts

Bug: 34103984
Test: RunSettingsRoboTest (no regresssion)
Change-Id: I71ddcdb3e1fc0df6cacb53583a4f7e8ae8d675f1