Make status bar battery scale with "status_bar_icon_scale_factor"

Test: BatteryViewModelTest
Test: Change to high res low density, where status_bar_icon_scale_factor
      is set to 2.0 and test it out
      adb shell density 88
      adb shell size 1920x1080
Flag: com.android.systemui.shared.status_bar_connected_displays
Bug: 413620149
Change-Id: I14a325729cadaeb2616033e5e1befea377e97c6d